Java全站乱码终极解决方案

package cn.itcast.filter;


import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Map;


import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;


/**
 * 解决get和post请求 全部乱码
 */
public class GenericEncodingFilter implements Filter {


@Override
public void destroy() {
}


@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
// 转型为与协议相关对象
HttpServletRequest httpServletRequest = (HttpServletRequest) request;
HttpServletResponse httpServletResponse = (HttpServletResponse) response;
httpServletResponse.setContentType("text/html;charset=utf-8");
// 对request包装增强
HttpServletRequest myrequest = new MyRequest(httpServletRequest);
chain.doFilter(myrequest, httpServletResponse);
}


@Override
public void init(FilterConfig filterConfig) throws ServletException {
}

}
// 自定义request对象
class MyRequest extends HttpServletRequestWrapper {

private HttpServletRequest request;

private boolean hasEncode;

public MyRequest(HttpServletRequest request) {
super(request);// super必须写
this.request = request;
}

// 对需要增强方法 进行覆盖
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 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();
}


@Override
public String getParameter(String name) {
Map parameterMap = getParameterMap();
String[] values = parameterMap.get(name);
if (values == null) {
return null;
}
return values[0]; // 取回参数的第一个值
}


@Override
public String[] getParameterValues(String name) {
Map parameterMap = getParameterMap();
String[] values = parameterMap.get(name);
return values;
}


}