SuperMap-iServer过滤请求返回值

目的：

iServer发布的arcgis地图服务中，由于tileinfo参数为null，导致用arcgis-ios客户端开发的APP闪退。通过过滤器将get请求的返回值修改

代码：

 package com.channel.filter;

 import java.io.ByteArrayOutputStream;
 import java.io.IOException;

 import javax.servlet.ServletOutputStream;
 import javax.servlet.WriteListener;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpServletResponseWrapper;

 /**
  * 返回值输出代理类
  *
  * @Title: ResponseWrapper
  * @Description:
  * @author kokJuis
  * @date 上午9:52:11
  */
 public class ResponseWrapper  extends HttpServletResponseWrapper {

     private ByteArrayOutputStream buffer;

     private ServletOutputStream out;

     public ResponseWrapper(HttpServletResponse httpServletResponse) {
         super(httpServletResponse);
         buffer = new ByteArrayOutputStream();
         out = new WrapperOutputStream(buffer);
     }

     @Override
     public ServletOutputStream getOutputStream() throws IOException {
         return out;
     }

     @Override
     public void flushBuffer() throws IOException {
         if (out != null) {
             out.flush();
         }
     }

     public byte[] getContent() throws IOException {
         flushBuffer();
         return buffer.toByteArray();
     }

     class WrapperOutputStream extends ServletOutputStream {
         private ByteArrayOutputStream bos;

         public WrapperOutputStream(ByteArrayOutputStream bos) {
             this.bos = bos;
         }

         @Override
         public void write(int b) throws IOException {
             bos.write(b);
         }

         @Override
         public boolean isReady() {

             // TODO Auto-generated method stub
             return false;

         }

         @Override
         public void setWriteListener(WriteListener arg0) {

             // TODO Auto-generated method stub

         }
     }

 }

在dofilter中实现返回值的替换

 package com.channel.filter;

 import java.io.IOException;
 import java.io.StringReader;

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

 import com.alibaba.fastjson.JSON;
 import com.alibaba.fastjson.JSONObject;

 /**
  * 返回值输出过滤器，这里用来加密返回值
  *
  * @Title: ResponseFilter
  * @Description:
  * @author kokJuis
  * @date 上午9:52:42
  */
 public class ResponseFilter implements Filter {

     public void doFilter(ServletRequest request, ServletResponse response,
             FilterChain filterChain) throws IOException, ServletException {
         ResponseWrapper wrapperResponse = new ResponseWrapper(
                 (HttpServletResponse) response);// 转换成代理类
         // 这里只拦截返回，直接让请求过去，如果在请求前有处理，可以在这里处理
         filterChain.doFilter(request, wrapperResponse);
         byte[] content = wrapperResponse.getContent();// 获取返回值
         // 判断是否有值
         if (content.length > 0) {

             String str = new String(content, "UTF-8");
             System.out.println(str);
             String ciphertext = null;

             // 判断下代码中是否包含tileinfo,包含则进行过滤，否则直接跳过响应体
             if (str.contains("tileInfo")) {
                 try {
                     // 获取返回值中tileinfo值，将null替换成{}测试
                     ciphertext = str.replaceFirst("null", "{}");
                     System.out.println("修改对应的参数！");
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
             }

             // 把返回值输出到客户端
             ServletOutputStream out = response.getOutputStream();
             out.write(ciphertext.getBytes());
             out.flush();
         }
     }

     public void init(FilterConfig arg0) throws ServletException {

     }

     public void destroy() {

     }
 }

配置说明：
1、jar包复制到iserver安装目录\webapps\iserver\WEB-INF\lib下
2、修改iserver安装目录\webapps\iserver\WEB-INF的web.xml
3、在web.xml中新增如下配置：

<!-- 过滤请求 -->
<filter>
<filter-name>ResponseFilter</filter-name>
<filter-class>com.channel.filter.ResponseFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>ResponseFilter</filter-name>
<url-pattern>/services/map-test2/arcgisrest/test/MapServer</url-pattern>
注：换成对应的的服务地址,只过滤指定的服务
</filter-mapping>

4、使用客户端动态出图，得到的返回值中tileinfo有null变为{}