Garbled problem
We often encounter many garbled problems in web development, such as request parameter garbled and response garbled, etc. Here are three ways to solve the garbled in development:
Method 1: Customize Filter
The role of Filter: intercept requests, release qualified requests, intercept non-qualified requests, and process requests.
**First step:** In this way, the custom class must first implement the javax.servlet.Filter interface, rewrite the three methods, and set the server code servletRequest.setCharacterEncoding("UTF-8");and browser code in the doFilter() method. servletResponse.setContentType("text/html;charset=UTF-8");
Finally, don’t forget to let it go. request,filterChain.doFilter(servletRequest, servletResponse);
package com.monster.Filter;
import javax.servlet.*;
import java.io.IOException;
/**
* @author Monster
* @version v1.0
* @time 02-28-2021 15:11:24
* @description:
*/
public class MyFilter implements Filter {
public void init(FilterConfig filterConfig) throws ServletException {
}
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
servletRequest.setCharacterEncoding("UTF-8");
servletResponse.setContentType("text/html;charset=UTF-8");
filterChain.doFilter(servletRequest, servletResponse);
}
public void destroy() {
}
}
**Step 2:** Configure the difference between
/ and /
in web.xml : / Only requests we write will be intercepted, and requests for files ending with .jsp will not be intercepted. / Intercept all requests.
<filter>
<filter-name>MyFilter</filter-name>
<filter-class>com.monster.Filter.MyFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>MyFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
Method 2: Use the filter provided by spring
Configure the content directly in the web.xml file:
<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>
But sometimes this processing method is not very good for get requests, we can modify the configuration file in Tomcat
<Connector URIEncoding="utf-8" port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
Method three: general filter
package com.monster.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.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 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++) {
try {
// 处理get乱码
values[i] = new String(values[i]
.getBytes("ISO-8859-1"), "utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
}
}
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();
String[] values = parameterMap.get(name);
return values;
}
}
This is written by a great god on the Internet. This is just for reference. Basically, Spring’s own way of dealing with garbled codes can solve almost all garbled problems. When we usually write code, we can set the code to write it as UTF-8 as much as possible. .