springMVC-乱码问题
1 编写一个出现乱码的情况
1.1 编写一个提交form表单的测试页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/e/t" method="get">
<input type="text" name="name">
<input type="submit">
</form>
</body>
</html>1.2 在后台编写对应的处理类
@Controller
public class Encoding {
@RequestMapping("/e/t")
public String test(Model model,String name){
System.out.println(name);
model.addAttribute("msg",name);
return "test";
}
}1.3 启动tomcat测试
访问测试页面并且提交一个中文参数
1.4 执行结果
2 解决乱码
2.1 尝试使用spring自带的乱码过滤器
2.1.1 需要依赖支持
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.0.RELEASE</version>
</dependency>2.1.2 配置web.xml文件
<!--配置springmvc的编码过滤器-->
<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>
</filter>
<filter-mapping>
<filter-name>encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>2.2 如果无效,尝试检查Tomcat配置文件
apache-tomcat-9.0.55\conf\server.xml
<Connector URIEncoding="utf-8" port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />2.3 如果还无效,就自定义一个过滤器
2.3.1 编写过滤器
package com.lv.filter;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.util.Map;
/**
* 解决get和post请求 全部乱码的过滤器
*/
public class GenericEncodingFilter implements Filter {
@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
//处理response的字符编码
HttpServletResponse myResponse=(HttpServletResponse) response;
myResponse.setContentType("text/html;charset=UTF-8");
// 转型为与协议相关对象
HttpServletRequest httpServletRequest = (HttpServletRequest) request;
// 对request包装增强
HttpServletRequest myRequest = new MyRequest(httpServletRequest);
chain.doFilter(myRequest, response);
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
}
//自定义request对象，HttpServletRequest的包装类
class MyRequest extends HttpServletRequestWrapper {
private final HttpServletRequest request;
//是否编码的标记
private boolean hasEncode;
//定义一个可以传入HttpServletRequest对象的构造函数，以便对其进行装饰
public MyRequest(HttpServletRequest request) {
super(request);// super必须写
this.request = request;
}
// 对需要增强方法 进行覆盖
@Override
public Map getParameterMap() {
// 先获得请求方式
String method = request.getMethod();
if (method.equalsIgnoreCase("post")) {
// post请求
try {
// 处理post乱码
request.setCharacterEncoding("utf-8");
return request.getParameterMap();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
} else if (method.equalsIgnoreCase("get")) {
// get请求
Map<String, String[]> parameterMap = request.getParameterMap();
if (!hasEncode) { // 确保get手动编码逻辑只运行一次
for (String parameterName : parameterMap.keySet()) {
String[] values = parameterMap.get(parameterName);
if (values != null) {
for (int i = 0; i < values.length; i++) {
// 处理get乱码
values[i] = new String(values[i]
.getBytes(StandardCharsets.ISO_8859_1), StandardCharsets.UTF_8);
}
}
}
hasEncode = true;
}
return parameterMap;
}
return super.getParameterMap();
}
//取一个值
@Override
public String getParameter(String name) {
Map<String, String[]> parameterMap = getParameterMap();
String[] values = parameterMap.get(name);
if (values == null) {
return null;
}
return values[0]; // 取回参数的第一个值
}
//取所有值
@Override
public String[] getParameterValues(String name) {
Map<String, String[]> parameterMap = getParameterMap();
return parameterMap.get(name);
}
}
2.3.2 配置web.xml文件
<!--自定义编码过滤器-->
<filter>
<filter-name>encoding</filter-name>
<filter-class>com.lv.filter.GenericEncodingFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
