JavaWeb——Get、Post請求中文亂碼問題

時間 2019-11-11

標籤 javaweb post 請求中文亂碼問題欄目 Java 简体版

原文原文鏈接

　　最近在重溫JavaWeb基礎內容，碰到了以前也時常遇到的中文亂碼問題，想着反正是常常要處理的，不如立即就把它整理出來放在博客裏，免得遇到時再去處處搜。javascript

　　1. Post請求亂碼的解決方案:html

　　手工建立一個過濾器實現javax.servlet.Filter接口:java

public class CharacterEncodingFilter implements Filter {

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

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        //解決以Post方式提交的中文亂碼問題
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        
        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {

    }

}

　　在web.xml中配置該過濾器:web

  <filter>
     <filter-name>CharacterEncodingFilter</filter-name>
     <filter-class>cn.lby.filter.CharacterEncodingFilter</filter-class>
  </filter>
  <filter-mapping>
     <filter-name>CharacterEncodingFilter</filter-name>
     <url-pattern>/*</url-pattern>
  </filter-mapping>

　　固然，實際開發中通常不會去本身作這個Filter，都是利用框架裏封裝好的，傳參也能經過配置來完成，十分方便，好比spring一般咱們會在web.xml中寫入下面的代碼:ajax

    <filter>
        <filter-name>CharacterEncodingFilter</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>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

2. Get請求亂碼的解決方案:spring

　　在字符過濾器中使用動態代理解決中文亂碼:tomcat

public class CharacterEncodingFilter implements Filter {

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

	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
        //解決以Post方式提交的中文亂碼問題
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        
        ServletRequest requestProxy = getHttpServletRequestProxy((HttpServletRequest)request);
        chain.doFilter(requestProxy, response);
	}

	@Override
	public void destroy() {

	}

    /**
    * @Method: getHttpServletRequestProxy
    * @Description: 獲取HttpServletRequest對象的代理對象
    * @param request
    * @return HttpServletRequest對象的代理對象
    */ 
    private ServletRequest getHttpServletRequestProxy(final HttpServletRequest request){
        ServletRequest proxy  = (ServletRequest) Proxy.newProxyInstance(
                CharacterEncodingFilter.class.getClassLoader(),
                request.getClass().getInterfaces(),
                new InvocationHandler(){
                    @Override
                    public Object invoke(Object proxy, Method method, Object[] args)
                            throws Throwable {
                        //若是請求方式是get而且調用的是getParameter方法
                        if (request.getMethod().equalsIgnoreCase("get") && method.getName().equals("getParameter")) {
                            //調用getParameter方法獲取參數的值
                            String value = (String) method.invoke(request, args);
                            if(value==null){
                                return null;
                            }
                            //解決以get方式提交的中文亂碼問題
                            return new String(value.getBytes("iso8859-1"),"UTF-8");
                        }else {
                            //直接調用相應的方法進行處理
                            return method.invoke(request, args);
                        }
                    }
                });
        //返回HttpServletRequest對象的代理對象
        return proxy;
    }
    

}

　　若是以爲上面的方式太繁瑣，也能夠經過修改 tomcat 的 server.xml 配置文件:app

<Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443"/>

　　改爲:框架

<Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443" useBodyEncodingForURI="true"/>

　　注: 若是是ajax發起的get請求中文依然會亂碼，這時候須要把 useBodyEncodingForURI="true" 改成 URIEncoding="UTF-8" 。jsp

　　下面是測試兩種亂碼問題解決方案的 demo ，若是懶得寫能夠參考一下:

　　首先是jsp頁面:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>使用字符過濾器解決解決get、post請求方式下的中文亂碼問題</title>
  body {
    text-align: center;
      padding: 60px 150px;
      margin-right: 150px;
      line-height: 2.0em;
    }
</head>

<body>
       
      <%--使用get的方式訪問 --%>
       <a onclick="myClick()" href="javascript:void(0)">超連接(get方式請求)</a>

       <hr/>

       <form action="EncodingServlet" method="post">
               用戶名：<input type="text" name="username" value="彬爺" />
           <input type="submit" value="post方式提交">
       </form>
       
       
       <script type="text/javascript">
              function myClick() {
          window.location.href = "EncodingServlet?username=彬爺";    
            }
       </script>
       
</body>

</html>

　　後臺服務:

public class EncodingServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public EncodingServlet() {
        super();
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String method = request.getMethod();
        PrintWriter out = response.getWriter();
        System.out.println("請求方式爲：" + method);
        out.write("請求方式爲：" + method);
        out.write("<br/>");
        System.out.println("請求參數爲：" + username);
        out.write("請求參數爲：" + username);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

}