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webappsiserverWEB-INFlib下
2、修改iserver安装目录webappsiserverWEB-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{}