JAVA-WEB 过滤器Filter 全局处理中文乱码

servlet

 

package web;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class FilterDemo extends HttpServlet {
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

		//获得传来的参数
		String name = request.getParameter("name");
		//测试服务器端收到的name
		System.out.println(name);
                //如果要getParameterMap获得参数就要对该方法进行增强
		Map map = request.getParameterMap();

		
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}

}

 

 

 

flter

package cn.itcast.crm.web.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;

/**
 * 通用编码解决方案
 * 
 */
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;
		// 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
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
	@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")) {//tomcat8.5已经处理了get中文可以将get中的代码注释掉
			// 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;
	}

}

 

 

 

web.xml设置

  
  	EncondeFilter
  	web.EncondeFilter
  
  
  	EncondeFilter
  	/*