JSP系列之页面跳转编码设置

短命女 2021-09-10 22:52 332阅读 0赞

在做JSP系统时经常遇到的就是编码问题

而这个服务器可以是Tomcat、Weblogic，Tomcat服务器默认的编码为iso-8859-1，Weblogic默认的编码为UTF-8，所以程序运行时要注意编码设置

现在我们以一个jsp页面的代码，解释这些编码设置pageEncoding="UTF-8"说的是页面的编码，比如标题栏<title>还有其它内容等等

<%@page import="java.net.URLDecoder"%>
    <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>My JSP 'test.jsp' starting page</title>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    	<meta http-equiv="pragma" content="no-cache">
    	<meta http-equiv="cache-control" content="no-cache">
    	<meta http-equiv="expires" content="0">    
    	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    	<meta http-equiv="description" content="This is my page">
    	
    	<style type="text/css">  
    		.news {  
    		    width: 800px;  
    		    margin: 0 auto;  
    		}  
    </style>  
    	
    
      </head>
      
      <body>
         <%  
            request.setCharacterEncoding("UTF-8"); 
            response.setContentType("text/html;charset=GBK");
          	String newsbody = new String(request.getParameter("editorValue").getBytes("iso-8859-1"),"UTF-8");  
        %>  
      
        <div class="news">  
            <%=newsbody%>  
      
        </div>  
    
      </body>
    </html>

String newsbody = new String(request.getParameter("editorValue").getBytes("iso-8859-1"),"UTF-8");

给一个编码过滤器参考

import java.io.IOException;
    import java.nio.charset.Charset;
    
    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.annotation.WebFilter;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletRequestWrapper;
    
    import org.apache.commons.lang.StringUtils;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    /**
     * @description: 编码过滤器, 解决get或post方式的乱码问题
     */
    @WebFilter(filterName = "encodingFilter", urlPatterns = "/*")
    public class EncodingFilter implements Filter {
    
    	private static final Logger logger = LoggerFactory.getLogger(EncodingFilter.class);
    
    	private String encode = "UTF-8";// 默认编码集
    	
        private String containers_encode="ISO8859-1";//web容器编码
    	
    	@Override
    	public void destroy() {
    		logger.info("====过滤器正在销毁====");
    	}
    
    	@Override
    	public void doFilter(ServletRequest request, ServletResponse response,
    			FilterChain chain) throws IOException, ServletException {
    		HttpServletRequest httpRequest = (HttpServletRequest) request;
    		if (httpRequest.getMethod().equals("POST")) {
    			logger.debug("post请求,直接设置编码");
    			// 直接设置编码
    			request.setCharacterEncoding(encode);
    		} else {
    			// 重写HttpServletRequestWrapper进行内部转码
    			logger.debug("get请求,尝试转码");
    			request = new Request(httpRequest);
    		}
    		// 设置返回客户端编码
    		response.setCharacterEncoding(encode);
    		chain.doFilter(request, response);// 交替权利给下一个过滤器或servlet服务
    	}
    
    	class Request extends HttpServletRequestWrapper {
    		/* 构造函数 */
    		public Request(HttpServletRequest request) {
    			super(request);
    		}
    
    		private HttpServletRequest getHttpServletRequest() {
    			return (HttpServletRequest) super.getRequest();
    		}
    
    		/**
    		 * 转换由表单读取的数据的内码
    		 * 
    		 * @param str
    		 * @return
    		 */
    		private String changeEncode(String str) {
    			if (needEncoding(str)) {
    				try {
    					byte[] bytes = str.getBytes(containers_encode);
    					logger.debug("数据:{} 转码结果:{}", str,
    							new String(bytes, encode));
    					return new String(bytes, encode);
    				} catch (Exception e) {
    					e.printStackTrace();
    				}
    				return null;
    			}
    			return str;
    		}
    
    		/* 判断字符串是否需要转码 */
    		private boolean needEncoding(String str) {
    			/* 如果为汉字，则不需要转码 */
    			return Charset.forName(containers_encode).newEncoder().canEncode(str);
    		}
    
    		@Override
    		/* 单个参数 */
    		public String getParameter(String arg) {
    			String value = getHttpServletRequest().getParameter(arg);
    			if (value != null) {
    				return changeEncode(getHttpServletRequest().getParameter(arg));
    			}
    			return getHttpServletRequest().getParameter(arg);
    		}
    
    		@Override
    		/* 多个参数 */
    		public String[] getParameterValues(String arg) {
    			String values[] = getHttpServletRequest().getParameterValues(arg);
    			if (values != null) {
    				for (int i = 0; i < values.length; i++) {
    					values[i] = changeEncode(values[i]);
    				}
    			}
    			return values;
    		}
    	}
    
    	@Override
    	public void init(FilterConfig config) throws ServletException {
    		logger.debug("====编码过滤器启动====");
    		/* 读取配置参数的编码集 */
    		String encoding = config.getInitParameter("encode");
    		if (StringUtils.isNotBlank(encoding)) {
    			this.encode = encoding;
    		}
    	}
    }