解決spring設置filter過濾器結合rest風格獲取post請求body參數輸入流問題

 由於最近在使用spring+jersey開發要設置基於servlet的filter。當在filter中通過request.getReader或者getInputStream讀取body中的json參數處理時，由於rest風格的jersey框架底層亦是基於同樣原理讀取post請求body中參數。因為request自身的原則：getReader或者getInputStream只能調用其中一個且只有一次可以正常獲取body中內容，導致在filter中通過getReader第一次讀取body中參數成功，當放行時，jersey中控制器執行時候，會出現異常：

java.lang.IllegalStateException: getReader() has already been called for this request。

 

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###           運行系統：windows8

###          JDK版本 ： JDK1.7

###          框架：spring3x + jersey2.x

###          開發IDE：MyEclipse

############################

1.0 在web.xml中配置spring過濾器filter，集成自定義filter

 

<filter>
        <filter-name>DelegateFilter</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
        <init-param>
            <param-name>targetBeanName</param-name>
            <param-value>myFilter</param-value> <!-- 自定義攔截器-->
        </init-param>
        <init-param>
            <param-name>targetFilterLifecycle</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>DelegateFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

2.0在spring配置文件application.xml中定義自定義filterbean。

 

 

<bean id="myFilter" class="com.cybbj.action.filter.FilterPost"></bean>

PS:若是在filter中想使用springIOC容器中其他bean.如其他service類。那么可以在該bean中配置。
例如在filter中需要注入公用commonSerivce
public class myFilter implements Filter{
    private CommonService commonService;

//需要setter
   .......
}

要想使用commonService而不拋出空指針異常，需要在bean中配置依賴：
<bean id="myFilter" class="com.cybbj.action.filter.FilterPost">
<property name="commonService"> <ref bean="commonService"/> <!-- 其中commonService是通過注解或者xml配置到IOC容器中的類--></property></bean>

 

3.0 自定義filter
原始代碼與運行結果如下：

 

public class FilterPost implements Filter{

    private Log log = LogFactory.getLog(FilterPost.class);

    String param = "";

    public void destroy() {
        // TODO Auto-generated method stub

    }

    public void doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
           HttpServletRequest request = null;
            if(req instanceof HttpServletRequest) {
               request = (HttpServletRequest)req;
            }

            if("POST".equalsIgnoreCase(request.getMethod())){
                param = this.getBodyString(request.getReader());
                log.info("filter讀取body中的參數>>>>>>>>>"+param);
                chain.doFilter(request, res);
    }

    }

    public void init(FilterConfig config) throws ServletException {

    }

    //獲取request請求body中參數
lic static String getBodyString(BufferedReader br) {
String inputLine;
     String str = "";
   try {
     while ((inputLine = br.readLine()) != null) {
      str += inputLine;
     }
     br.close();
   } catch (IOException e) {
     System.out.println("IOException: " + e);
   }
   return str;

 

4.0基於jersey的controller中post請求處理

 

@POST
@Path("/postJson")
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public Map<String, String> postByJson(Map<String, Object> jsonParam) {

    JSONObject jo = new JSONObject(jsonParam);
    System.out.println(jsonParam);
    Map<String, String> param = new HashMap<String, String>();
    param.put("name", jo.getString("name").length()==0? "" : jo.getString("name"));
    param.put("age", jo.getString("age").length()==0  ? "" :jo.getString("age"));
    param.put("status", "200");
    param.put("Msg", "ok,success");
    return param;
}

 

 

5. 拋出異常
java.lang.IllegalStateException: getReader() has already been called for this request
    at org.apache.catalina.connector.Request.getInputStream(Request.java:1085)

解決方法：

 

結合JODD開源框架，且在Filter中將ServletRequest替換為ServletRequestWrapper 來解決該問題。

 

 

A：添加jodd支持：

在pom.xml中添加對jodd的依賴：

 

<!-- https://mvnrepository.com/artifact/org.jodd/jodd-core -->
<dependency>
</span><groupId>org.jodd</groupId>
</span><artifactId>jodd-core</artifactId>
</span><version>3.4.8</version>
</dependency>

 

 

B:結合jodd創建自定義ServletRequestWrapper

 

public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper{

     private final byte[] body; //用於保存讀取body中數據

        public BodyReaderHttpServletRequestWrapper(HttpServletRequest request)
    throws IOException {
            super(request);
            body = StreamUtil.readBytes(request.getReader(), "UTF-8");
        }

        @Override
        public BufferedReader getReader() throws IOException {
            return new BufferedReader(new InputStreamReader(getInputStream()));
        }

        @Override
        public ServletInputStream getInputStream() throws IOException {
            final ByteArrayInputStream bais = new ByteArrayInputStream(body);
            return new ServletInputStream() {

                @Override
                public int read() throws IOException {
                    return bais.read();
                }

                @Override
                public boolean isFinished() {
                    // TODO Auto-generated method stub
                    return false;
                }

                @Override
                public boolean isReady() {
                    // TODO Auto-generated method stub
                    return false;
                }

                @Override
                public void setReadListener(ReadListener arg0) {
                    // TODO Auto-generated method stub

                }
            };
        }
}

C:用wrapper替換request修改filter

 

 

public void doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
          String method = "GET";
           ServletRequest requestWrapper = null;
            if(req instanceof HttpServletRequest) {
                method = ((HttpServletRequest) req).getMethod();
                requestWrapper = new BodyReaderHttpServletRequestWrapper((HttpServletRequest) req);  //替換
            }

            if("POST".equalsIgnoreCase(method)){
                param = this.getBodyString(requestWrapper.getReader());
                log.info("filter讀取body中的參數>>>>>>>>>"+param);
                chain.doFilter(requestWrapper, res);
    }

D:請求測試

 

請求成功................

 

參考文章：http://liwx2000.iteye.com/blog/1542431

 

原文地址：https://blog.csdn.net/xiansky2015/article/details/52013690