技术标签: spring java 萌妹子的基础知识专栏
到目前为止我们编写的所有Controller的方法的返回值都是String类型,但是大家应该都知道,我们有时候数据传递特别是在ajax中,我们返回的数据经常需要使用json,那么如何来保证返回的数据的是json格式呢?使用@ResponseBody注解
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.mashibing</groupId>
<artifactId>springmv_ajax</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.2.3.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-web -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>5.2.3.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.3.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jsp-api</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.10.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.10.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.10.3</version>
</dependency>
</dependencies>
</project>
springmvc.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="com.mashibing"></context:component-scan>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/page/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<mvc:default-servlet-handler></mvc:default-servlet-handler>
<mvc:annotation-driven></mvc:annotation-driven>
</beans>
JsonController.java
package com.mashibing.controller;
import com.mashibing.bean.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
@Controller
public class JsonController {
@ResponseBody
@RequestMapping("/json")
public List<User> json(){
List<User> list = new ArrayList<User>();
list.add(new User(1,"zhangsan",12,"男",new Date(),"[email protected]"));
list.add(new User(2,"zhangsan2",12,"男",new Date(),"[email protected]"));
list.add(new User(3,"zhangsan3",12,"男",new Date(),"[email protected]"));
return list;
}
}
User.java
package com.mashibing.bean;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonIgnore;
import java.util.Date;
public class User {
private Integer id;
private String name;
private Integer age;
private String gender;
@JsonFormat( pattern = "yyyy-MM-dd")
private Date birth;
@JsonIgnore
private String email;
public User() {
}
public User(Integer id, String name, Integer age, String gender, Date birth, String email) {
this.id = id;
this.name = name;
this.age = age;
this.gender = gender;
this.birth = birth;
this.email = email;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirth() {
return birth;
}
public void setBirth(Date birth) {
this.birth = birth;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", age=" + age +
", gender='" + gender + '\'' +
", birth=" + birth +
", email='" + email + '\'' +
'}';
}
}
同时@ResponseBody可以直接将返回的字符串数据作为响应内容
package com.mashibing.controller;
import com.mashibing.bean.User;
import org.springframework.http.HttpEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class OtherController {
@ResponseBody
@RequestMapping("/testResponseBody")
public String testResponseBody(){
return "<h1>success</h1>";
}
}
ajax.jsp
<%@ page import="java.util.Date" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script type="text/javascript" src="script/jquery-1.9.1.min.js"></script>
</head>
<%
pageContext.setAttribute("ctp",request.getContextPath());
%>
<body>
<%=new Date()%>
<a href="${ctp}/json">获取用户信息</a>
<div>
</div>
<script type="text/javascript">
$("a:first").click(function () {
$.ajax({
url:"${ctp}/json",
type:"GET",
success:function (data) {
console.log(data)
$.each(data,function() {
var user = this.id+"--"+this.name+"--"+this.age+"--"+this.gender+"--"+this.birth+"--"+this.email;
$("div").append(user+'<br/>');
})
}
});
return false;
});
</script>
</body>
</html>
testOther.jsp
<%--
Created by IntelliJ IDEA.
User: root
Date: 2020/3/13
Time: 15:04
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<%
pageContext.setAttribute("ctp",request.getContextPath());
%>
<head>
<title>Title</title>
</head>
<body>
<form action="${ctp}/testRequestBody" method="post" enctype="multipart/form-data">
<input name="username" value="zhangsan"><br>
<input name="password" value="123456"><br>
<input type="file" name="file" ><br>
<input type="submit"><br>
</form>
</body>
</html>
OtherController.java
package com.mashibing.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class OtherController {
@RequestMapping("/testRequestBody")
public String testRequestBody(@RequestBody String body){
System.out.println("请求体:"+body);
return "success";
}
}
同时@RequestBody能够接受json格式的请求数据:
testOther.jsp
<%--
Created by IntelliJ IDEA.
User: root
Date: 2020/3/13
Time: 15:04
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<script type="text/javascript" src="script/jquery-1.9.1.min.js"></script>
<html>
<%
pageContext.setAttribute("ctp",request.getContextPath());
%>
<head>
<title>Title</title>
</head>
<body>
<form action="${ctp}/testRequestBody" method="post" enctype="multipart/form-data">
<input name="username" value="zhangsan"><br>
<input name="password" value="123456"><br>
<input type="file" name="file" ><br>
<input type="submit"><br>
</form>
<hr/>
<a href="${ctp}/testRequestJson">发送json数据</a>
<script type="text/javascript">
$("a:first").click(function () {
var user = {id:"1",name:"zhangsan",age:"12",gender:"男",birth:"2020-3-13",email:"[email protected]"};
var userJson = JSON.stringify(user);
$.ajax({
url:"${ctp}/testRequestJson",
type:"POST",
data:userJson,
contentType:"application/json",
success:function (data) {
alert(data);
}
});
return false;
});
</script>
</body>
</html>
OtherController.java
package com.mashibing.controller;
import com.mashibing.bean.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class OtherController {
@RequestMapping("/testRequestBody")
public String testRequestBody(@RequestBody String body){
System.out.println("请求体:"+body);
return "success";
}
@RequestMapping("/testRequestJson")
public String testRequestBody(@RequestBody User user){
System.out.println("对象:"+user);
return "success";
}
}
在接受请求的时候还可以使用HttpEntity对象,用来接受参数,可以获取请求头信息。
package com.mashibing.controller;
import com.mashibing.bean.User;
import org.springframework.http.HttpEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class OtherController {
@RequestMapping("/testHttpEntity")
public String testRequestBody(HttpEntity<String> httpEntity){
System.out.println(httpEntity);
return "success";
}
}
package com.mashibing.controller;
import com.mashibing.bean.User;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.util.MultiValueMap;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class OtherController {
@RequestMapping("/testResponseEntity")
public ResponseEntity<String> testResponseEntity(){
String body = "<h1>hello</h1>";
MultiValueMap<String,String> header = new HttpHeaders();
header.add("Set-Cookie","name=zhangsan");
return new ResponseEntity<String>(body,header, HttpStatus.OK);
}
}
package com.mashibing.controller;
import com.mashibing.bean.User;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.util.MultiValueMap;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
@Controller
public class OtherController {
@RequestMapping("/download")
public ResponseEntity<byte[]> download(HttpServletRequest request) throws Exception {
//获取要下载文件的路径及输入流对象
ServletContext servletContext = request.getServletContext();
String realPath = servletContext.getRealPath("/script/jquery-1.9.1.min.js");
FileInputStream fileInputStream = new FileInputStream(realPath);
byte[] bytes = new byte[fileInputStream.available()];
fileInputStream.read(bytes);
fileInputStream.close();
//将要下载文件内容返回
HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.set("Content-Disposition","attachment;filename=jquery-1.9.1.min.js");
return new ResponseEntity<byte[]>(bytes,httpHeaders,HttpStatus.OK);
}
}
Spring MVC 为文件上传提供了直接的支持,这种支持是通过即插即用的 MultipartResolver 实现的。Spring 用 Jakarta Commons FileUpload 技术实现了一个 MultipartResolver 实现类:CommonsMultipartResovler
Spring MVC 上下文中默认没有装配 MultipartResovler,因此默认情况下不能处理文件的上传工作,如果想使用 Spring 的文件上传功能,需现在上下文中配置 MultipartResolver。
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.mashibing</groupId>
<artifactId>springmvc_upload</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.2.3.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-web -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>5.2.3.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.3.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jsp-api</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.10.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.10.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.10.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/commons-io/commons-io -->
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.6</version>
</dependency>
<!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload -->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency>
</dependencies>
</project>
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<filter>
<filter-name>encoding</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
springmvc.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<mvc:default-servlet-handler></mvc:default-servlet-handler>
<mvc:annotation-driven></mvc:annotation-driven>
<context:component-scan base-package="com.mashibing"></context:component-scan>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/page/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="UTF-8"></property>
<property name="maxUploadSize" value="1024000"></property>
</bean>
</beans>
index.jsp
<%--
Created by IntelliJ IDEA.
User: root
Date: 2020/3/13
Time: 17:00
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<form action="testUpload" method="post" enctype="multipart/form-data">
文件: <input type="file" name="file"/><br><br>
描述: <input type="text" name="desc"/><br><br>
<input type="submit" value="提交"/>
</form>
</body>
</html>
UploadHandler.java
package com.mashibing.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
@Controller
public class UploadHandler {
@RequestMapping(value = "/testUpload", method = RequestMethod.POST)
public String testUpload(@RequestParam(value = "desc", required = false) String desc, @RequestParam("file") MultipartFile multipartFile) throws IOException {
System.out.println("desc : " + desc);
System.out.println("OriginalFilename : " + multipartFile.getOriginalFilename());
multipartFile.transferTo(new File("D:\\file\\"+multipartFile.getOriginalFilename()));
return "success"; //增加成功页面: /views/success.jsp
}
}
success.jsp
<%--
Created by IntelliJ IDEA.
User: root
Date: 2020/3/13
Time: 17:03
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
success
</body>
</html>
如果是多文件上传,那么又改如何处理呢?
index.jsp
<%--
Created by IntelliJ IDEA.
User: root
Date: 2020/3/13
Time: 17:00
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<form action="testUpload" method="post" enctype="multipart/form-data">
文件: <input type="file" name="file"/><br><br>
文件: <input type="file" name="file"/><br><br>
文件: <input type="file" name="file"/><br><br>
描述: <input type="text" name="desc"/><br><br>
<input type="submit" value="提交"/>
</form>
</body>
</html>
UploadHandler.java
package com.mashibing.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
@Controller
public class UploadHandler {
@RequestMapping(value = "/testUpload", method = RequestMethod.POST)
public String testUpload(@RequestParam(value = "desc", required = false) String desc, @RequestParam("file") MultipartFile[] multipartFile) throws IOException {
System.out.println("desc : " + desc);
for (MultipartFile file : multipartFile) {
if (!file.isEmpty()) {
System.out.println("OriginalFilename : " + file.getOriginalFilename());
file.transferTo(new File("D:\\file\\" + file.getOriginalFilename()));
}
}
return "success"; //增加成功页面: /views/success.jsp
}
}
SpringMVC提供了拦截器机制,允许运行目标方法之前进行一些拦截工作或者目标方法运行之后进行一下其他相关的处理。自定义的拦截器必须实现HandlerInterceptor接口。
preHandle():这个方法在业务处理器处理请求之前被调用,在该方法中对用户请求 request 进行处理。如果程序员决定该拦截器对请求进行拦截处理后还要调用其他的拦截器,或者是业务处理器去进行处理,则返回true;如果程序员决定不需要再调用其他的组件去处理请求,则返回false
postHandle():这个方法在业务处理器处理完请求后,但是DispatcherServlet 向客户端返回响应前被调用,在该方法中对用户请求request进行处理。
afterCompletion():这个方法在DispatcherServlet完全处理完请求后被调用,可以在该方法中进行一些资源清理的操作。
MyFirstInterceptor.java
package com.mashibing.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MyFirstInterceptor implements HandlerInterceptor {
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println(this.getClass().getName()+"------->preHandle");
return true;
}
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println(this.getClass().getName()+"------->postHandle");
}
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println(this.getClass().getName()+"------->afterCompletion");
}
}
TestInterceptorController.java
package com.mashibing.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class TestInterceptorController {
@RequestMapping("test01")
public String test01(){
System.out.println("test01");
return "success";
}
}
springmvc.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<mvc:default-servlet-handler></mvc:default-servlet-handler>
<mvc:annotation-driven></mvc:annotation-driven>
<context:component-scan base-package="com.mashibing"></context:component-scan>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/page/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<mvc:interceptors>
<bean class="com.mashibing.interceptor.MyFirstInterceptor"></bean>
</mvc:interceptors>
</beans>
success.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<% System.out.println("success.jsp");%>
success
</body>
</html>
通过运行结果能够发现拦截器的执行顺序如下:
可以看到先执行拦截器的preHandle方法----》执行目标方法----》执行拦截器的postHandle方法----》执行页面跳转----》执行拦截器的afterCompletion方法
在配置拦截器的时候有两个需要注意的点:
1、如果prehandle方法返回值 为false,那么意味着不放行,那么就会造成后续的所有操作都中断
2、如果执行到方法中出现异常,那么后续流程不会处理但是afterCompletion方法会执行
再添加另外一个拦截器
MySecondInterceptor.java
package com.mashibing.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MySecondInterceptor implements HandlerInterceptor {
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println(this.getClass().getName()+"------->preHandle");
return true;
}
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println(this.getClass().getName()+"------->postHandle");
}
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println(this.getClass().getName()+"------->afterCompletion");
}
}
看到如下执行顺序:
调整两个拦截器的配置顺序:
大家可以看到对应的效果,谁先执行取决于配置的顺序。
拦截器的preHandle是按照顺序执行的
拦截器的postHandle是按照逆序执行的
拦截器的afterCompletion是按照逆序执行的
如果执行的时候核心的业务代码出问题了,那么已经通过的拦截器的afterCompletion会接着执行。
1、过滤器是基于函数回调的,而拦截器是基于java反射的
2、过滤器依赖于servlet容器,而拦截器不依赖与Servlet容器
3、过滤器几乎对所有的请求都起作用,而拦截器只能对action请求起作用
4、拦截器可以访问action的上下文,而过滤器不可以
5、在controller的生命周期中,拦截器可以多次调用,而过滤器只能在web容器初始化的时候初始化一次,后续匹配的所有请求都会经过过滤器来进行过滤
在日常工作中,如果你的网站需要给不同语言地区的人进行查看,此时就需要使用国际化的基本操作,springmvc的国际化操作比较容易。
index.jsp
<%--
Created by IntelliJ IDEA.
User: root
Date: 2020/3/13
Time: 17:00
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<a href="i18n">国际化页面登录</a>
</body>
</html>
login.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1><fmt:message key="welcomeinfo"/></h1>
<form action="login" method="post" >
<fmt:message key="username"/>: <input type="text" name="username"/><br><br>
<fmt:message key="password"/>: <input type="password" name="password"/><br><br>
<input type="submit" value="<fmt:message key="loginBtn"/>"/>
</form>
</body>
</html>
I18nController.java
package com.mashibing.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class I18nController {
@RequestMapping("i18n")
public String i18n(){
return "login";
}
}
login_en_US.properties
welcomeinfo=welcome to mashibing.com
username=USERNAME
password=PASSWORD
loginBtn=LOGIN
login_zh_CN.properties
welcomeinfo=欢迎进入马士兵教育
username=用户名
password=密码
loginBtn=登录
springmvc.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<mvc:default-servlet-handler></mvc:default-servlet-handler>
<mvc:annotation-driven></mvc:annotation-driven>
<context:component-scan base-package="com.mashibing"></context:component-scan>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/page/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="login"></property>
</bean>
</beans>
其实SpringMVC中国际化的处理非常简单,就是按照浏览器所带来的语言信息决定的。
Locale locale = request.getLocale();//获取浏览器的区域信息
在DispatcherServlet中会包含一个组件,用来专门获取区域信息
通过图片能够发现,默认调用的是org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver类
在程序中可以获取Locale的相关信息:
package com.mashibing.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.MessageSource;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import java.util.Locale;
@Controller
public class I18nController {
@Autowired
private MessageSource messageSource;
@RequestMapping("i18n")
public String i18n(Locale locale){
System.out.println(locale);
String username = messageSource.getMessage("username", null, locale);
System.out.println(username);
return "login";
}
}
login.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1><fmt:message key="welcomeinfo"/></h1>
<form action="login" method="post" >
<fmt:message key="username"/>: <input type="text" name="username"/><br><br>
<fmt:message key="password"/>: <input type="password" name="password"/><br><br>
<input type="submit" value="<fmt:message key="loginBtn"/>"/>
<a href="i18n?locale=zh_CN">中文</a><a href="i18n?locale=en_US">英文</a>
</form>
</body>
</html>
MyLocaleResolver.java
package com.mashibing;
import org.springframework.web.servlet.LocaleResolver;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Locale;
public class MyLocaleResolver implements LocaleResolver {
/**
* 解析并返回locale
* @param request
* @return
*/
@Override
public Locale resolveLocale(HttpServletRequest request) {
Locale locale = null;
String localeStr = request.getParameter("locale");
if(localeStr!=null && ! "".equals(localeStr)){
locale = new Locale(localeStr.split("_")[0],localeStr.split("_")[1]);
}else{
locale = request.getLocale();
}
return locale;
}
/**
* 不支持设置locale的信息
* @param request
* @param response
* @param locale
*/
@Override
public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) {
throw new UnsupportedOperationException(
"Cannot change HTTP accept header - use a different locale resolution strategy");
}
}
springmvc.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<mvc:default-servlet-handler></mvc:default-servlet-handler>
<mvc:annotation-driven></mvc:annotation-driven>
<context:component-scan base-package="com.mashibing"></context:component-scan>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/page/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="login"></property>
</bean>
<!--配置区域信息解析器-->
<bean id="localeResolver" class="com.mashibing.MyLocaleResolver"></bean>
</beans>
除了可以自定义区域信息解析器之外,我们还可以使用SpringMVC中自带的SessionLocaleResolver:
I18nController.java
package com.mashibing.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.MessageSource;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.i18n.SessionLocaleResolver;
import javax.servlet.http.HttpSession;
import java.util.Locale;
@Controller
public class I18nController {
@Autowired
private MessageSource messageSource;
@RequestMapping("i18n")
public String i18n(@RequestParam(value = "locale",defaultValue = "zh_CN") String localeStr,Locale locale, HttpSession session){
Locale l = null;
if(localeStr!=null && ! "".equals(localeStr)){
l = new Locale(localeStr.split("_")[0],localeStr.split("_")[1]);
}else{
l = locale;
}
session.setAttribute(SessionLocaleResolver.class.getName() + ".LOCALE",l);
return "login";
}
}
springmvc.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<mvc:default-servlet-handler></mvc:default-servlet-handler>
<mvc:annotation-driven></mvc:annotation-driven>
<context:component-scan base-package="com.mashibing"></context:component-scan>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/page/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="login"></property>
</bean>
<!--配置区域信息解析器-->
<!-- <bean id="localeResolver" class="com.mashibing.MyLocaleResolver"></bean>-->
<bean id="localeResolver" class="org.springframework.web.servlet.i18n.SessionLocaleResolver"></bean>
</beans>
使用LocaleChangeInterceptor来实现国际化:
springmvc.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<mvc:default-servlet-handler></mvc:default-servlet-handler>
<mvc:annotation-driven></mvc:annotation-driven>
<context:component-scan base-package="com.mashibing"></context:component-scan>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/page/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<!-- <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">-->
<!-- <property name="defaultEncoding" value="UTF-8"></property>-->
<!-- <property name="maxUploadSize" value="1024000"></property>-->
<!-- </bean>-->
<!-- <mvc:interceptors>-->
<!-- <bean class="com.mashibing.interceptor.MySecondInterceptor"></bean>-->
<!-- <bean class="com.mashibing.interceptor.MyFirstInterceptor"></bean>-->
<!-- </mvc:interceptors>-->
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="login"></property>
</bean>
<!--配置区域信息解析器-->
<!-- <bean id="localeResolver" class="com.mashibing.MyLocaleResolver"></bean>-->
<bean id="localeResolver" class="org.springframework.web.servlet.i18n.SessionLocaleResolver"></bean>
<mvc:interceptors>
<bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"></bean>
</mvc:interceptors>
</beans>
I18nController.java
package com.mashibing.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.MessageSource;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.i18n.SessionLocaleResolver;
import javax.servlet.http.HttpSession;
import java.util.Locale;
@Controller
public class I18nController {
@Autowired
private MessageSource messageSource;
@RequestMapping("i18n")
public String i18n(@RequestParam(value = "locale",defaultValue = "zh_CN") String localeStr,Locale locale, HttpSession session){
// Locale l = null;
// if(localeStr!=null && ! "".equals(localeStr)){
// l = new Locale(localeStr.split("_")[0],localeStr.split("_")[1]);
// }else{
// l = locale;
// }
// session.setAttribute(SessionLocaleResolver.class.getName() + ".LOCALE",l);
return "login";
}
}
在SpringMVC中拥有一套非常强大的异常处理机制,SpringMVC通过HandlerExceptionResolver处理程序的异常,包括请求映射,数据绑定以及目标方法的执行时发生的异常。
在容器启动好,进入DispatcherServlet之后,会对HandlerExceptionResolver进行初始化操作:
会默认的从DispatcherServlet.properties中找到对应的异常处理类:
#默认的处理类
org.springframework.web.servlet.HandlerExceptionResolver=
#处理@ExceptionHandler
org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver,\
#处理@ResponseStatus,给自定义异常使用
org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver,\
#判断是否是SpringMVC自带异常
org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver
自己定义异常处理方式:
index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<a href="exception1">自己处理异常</a>
</body>
</html>
ExceptionController.java
package com.mashibing.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import javax.jws.WebParam;
@Controller
public class ExceptionController {
@RequestMapping("exception1")
public String exception(){
System.out.println("exception.......");
System.out.println(10/0);
return "success";
}
@ExceptionHandler(value = {
ArithmeticException.class})
public ModelAndView handlerException(Exception exception){
ModelAndView mv = new ModelAndView();
mv.setViewName("error");
mv.addObject("ex",exception);
return mv;
}
}
error.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
我的出错页面:
错误信息:${ex}
</body>
</html>
在一个类中可能会包含多个异常的处理方法,在不同的方法上可以使用不同范围的异常,在查找的时候会优先调用范围小的异常处理;
package com.mashibing.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import javax.jws.WebParam;
@Controller
public class ExceptionController {
@RequestMapping("exception1")
public String exception(){
System.out.println("exception.......");
System.out.println(10/0);
return "success";
}
@ExceptionHandler(value = {
ArithmeticException.class})
public ModelAndView handlerException1(Exception exception){
System.out.println("handlerException1........");
ModelAndView mv = new ModelAndView();
mv.setViewName("error");
mv.addObject("ex",exception);
return mv;
}
@ExceptionHandler(value = {
Exception.class})
public ModelAndView handlerException2(Exception exception){
System.out.println("handlerException2........");
ModelAndView mv = new ModelAndView();
mv.setViewName("error");
mv.addObject("ex",exception);
return mv;
}
}
在不同的类中可能会包含不同的异常处理,因此我们需要定义一个全局的异常控制器,使用@ControllerAdvice注解标注,如果本类跟全局都有相关异常的处理,那么会优先使用本类的。
package com.mashibing.controller;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;
@ControllerAdvice
public class MyGlobalExceptionHandler {
@ExceptionHandler(value = {
ArithmeticException.class})
public ModelAndView handlerException1(Exception exception){
System.out.println("handlerException1........");
ModelAndView mv = new ModelAndView();
mv.setViewName("error");
mv.addObject("ex",exception);
return mv;
}
}
@ResponseStatus的使用:
@ResponseStatus可以标注到方法上,但是标注在方法之后可能导致该方法无法被访问,因此更多的是在自定义类上
package com.mashibing.controller;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.servlet.ModelAndView;
import javax.jws.WebParam;
@Controller
public class ExceptionController {
@ResponseStatus(reason = "不知道什么原因,反正错误",value = HttpStatus.NOT_ACCEPTABLE)
@RequestMapping("exception1")
public String exception(){
System.out.println("exception.......");
return "success";
}
}
@ResponseStatus作用在类上
UserNameException.java
package com.mashibing.controller;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;
@ResponseStatus(reason = "名字不是admin",value = HttpStatus.NOT_ACCEPTABLE)
public class UserNameException extends RuntimeException {
}
ExceptionController.java
package com.mashibing.controller;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.servlet.ModelAndView;
import javax.jws.WebParam;
@Controller
public class ExceptionController {
@RequestMapping("exception1")
public String exception(){
System.out.println("exception.......");
return "success";
}
@RequestMapping("exception2")
public String exception2(String username){
System.out.println("exception2222.......");
if ("admin".equals(username)){
return "success";
}else{
throw new UserNameException();
}
}
}
springmvc自定义的异常:
index.jsp
<%--
Created by IntelliJ IDEA.
User: root
Date: 2020/3/13
Time: 17:00
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<a href="exception1">自己处理异常</a>
<a href="exception2?username=zhangsan">自定义异常处理</a>
<a href="exception3">Springmvc自己异常处理</a>
</body>
</html>
ExceptionController.java
package com.mashibing.controller;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.servlet.ModelAndView;
import javax.jws.WebParam;
@Controller
public class ExceptionController {
@RequestMapping("exception1")
public String exception(){
System.out.println("exception.......");
return "success";
}
@RequestMapping("exception2")
public String exception2(String username){
System.out.println("exception2222.......");
if ("admin".equals(username)){
return "success";
}else{
throw new UserNameException();
}
}
@RequestMapping(value = "exception3",method = RequestMethod.POST)
public String exception3(String username){
System.out.println("exception3.......");
return "success";
}
}
文章浏览阅读1.6k次。安装配置gi、安装数据库软件、dbca建库见下:http://blog.csdn.net/kadwf123/article/details/784299611、检查集群节点及状态:[root@rac2 ~]# olsnodes -srac1 Activerac2 Activerac3 Activerac4 Active[root@rac2 ~]_12c查看crs状态
文章浏览阅读1.3w次,点赞45次,收藏99次。我个人用的是anaconda3的一个python集成环境,自带jupyter notebook,但在我打开jupyter notebook界面后,却找不到对应的虚拟环境,原来是jupyter notebook只是通用于下载anaconda时自带的环境,其他环境要想使用必须手动下载一些库:1.首先进入到自己创建的虚拟环境(pytorch是虚拟环境的名字)activate pytorch2.在该环境下下载这个库conda install ipykernelconda install nb__jupyter没有pytorch环境
文章浏览阅读5.2k次,点赞19次,收藏28次。选择scoop纯属意外,也是无奈,因为电脑用户被锁了管理员权限,所有exe安装程序都无法安装,只可以用绿色软件,最后被我发现scoop,省去了到处下载XXX绿色版的烦恼,当然scoop里需要管理员权限的软件也跟我无缘了(譬如everything)。推荐添加dorado这个bucket镜像,里面很多中文软件,但是部分国外的软件下载地址在github,可能无法下载。以上两个是官方bucket的国内镜像,所有软件建议优先从这里下载。上面可以看到很多bucket以及软件数。如果官网登陆不了可以试一下以下方式。_scoop-cn
文章浏览阅读4.5k次,点赞2次,收藏3次。首先要有一个color-picker组件 <el-color-picker v-model="headcolor"></el-color-picker>在data里面data() { return {headcolor: ’ #278add ’ //这里可以选择一个默认的颜色} }然后在你想要改变颜色的地方用v-bind绑定就好了,例如:这里的:sty..._vue el-color-picker
文章浏览阅读640次。基于芯片日益增长的问题,所以内核开发者们引入了新的方法,就是在内核中只保留函数,而数据则不包含,由用户(应用程序员)自己把数据按照规定的格式编写,并放在约定的地方,为了不占用过多的内存,还要求数据以根精简的方式编写。boot启动时,传参给内核,告诉内核设备树文件和kernel的位置,内核启动时根据地址去找到设备树文件,再利用专用的编译器去反编译dtb文件,将dtb还原成数据结构,以供驱动的函数去调用。firmware是三星的一个固件的设备信息,因为找不到固件,所以内核启动不成功。_exynos 4412 刷机
文章浏览阅读2w次,点赞24次,收藏42次。Linux系统配置jdkLinux学习教程,Linux入门教程(超详细)_linux配置jdk
文章浏览阅读3.3k次,点赞5次,收藏19次。xlabel('\delta');ylabel('AUC');具体符号的对照表参照下图:_matlab微米怎么输入
文章浏览阅读119次。顺序读写指的是按照文件中数据的顺序进行读取或写入。对于文本文件,可以使用fgets、fputs、fscanf、fprintf等函数进行顺序读写。在C语言中,对文件的操作通常涉及文件的打开、读写以及关闭。文件的打开使用fopen函数,而关闭则使用fclose函数。在C语言中,可以使用fread和fwrite函数进行二进制读写。 Biaoge 于2024-03-09 23:51发布 阅读量:7 ️文章类型:【 C语言程序设计 】在C语言中,用于打开文件的函数是____,用于关闭文件的函数是____。
文章浏览阅读3.4k次,点赞2次,收藏13次。跟随鼠标移动的粒子以grid(SOP)为partical(SOP)的资源模板,调整后连接【Geo组合+point spirit(MAT)】,在连接【feedback组合】适当调整。影响粒子动态的节点【metaball(SOP)+force(SOP)】添加mouse in(CHOP)鼠标位置到metaball的坐标,实现鼠标影响。..._touchdesigner怎么让一个模型跟着鼠标移动
文章浏览阅读178次。项目运行环境配置:Jdk1.8 + Tomcat7.0 + Mysql + HBuilderX(Webstorm也行)+ Eclispe(IntelliJ IDEA,Eclispe,MyEclispe,Sts都支持)。项目技术:Springboot + mybatis + Maven +mysql5.7或8.0+html+css+js等等组成,B/S模式 + Maven管理等等。环境需要1.运行环境:最好是java jdk 1.8,我们在这个平台上运行的。其他版本理论上也可以。_基于java技术的停车场管理系统实现与设计
文章浏览阅读3.5k次。前言对于MediaPlayer播放器的源码分析内容相对来说比较多,会从Java-&amp;gt;Jni-&amp;gt;C/C++慢慢分析,后面会慢慢更新。另外,博客只作为自己学习记录的一种方式,对于其他的不过多的评论。MediaPlayerDemopublic class MainActivity extends AppCompatActivity implements SurfaceHolder.Cal..._android多媒体播放源码分析 时序图
文章浏览阅读2.4k次,点赞41次,收藏13次。java 数据结构与算法 ——快速排序法_快速排序法