JSONObject[“data”]isnotaJSONArra

JSONObject[“data”] is not a JSONArray解决办法
错误：JSONObject[“data”] is not a JSONArray

JSONObject[“data”] 不是一个 JSONArray

原因：

JSONObject json = AcceptUtil.acceptFile(req);

JSONArray data = json.getJSONArray(“data”);

先从前端获取JSONObject 里的数据，再获取JSONObject 里的data数组，这里会存在一个问题，data如果没有值就会报上面的错误。

解决办法：

使用if(0!=json.get(“data”).toString().length())进行判断，当data数组的长度不为0时，再去获取data数组

if(0!=json.get("data").toString().length()){

JSONArray data = json.getJSONArray("data");

}

思路：

先在控制台打印json数据：

json:{“data”:" “,“type”:1}

发现data里面没有值，就想能否去判断一下，当data里面有值时，再去获取data里的数据。没有值是不是意味着data为空呢，就去判断data是否为null，然后测试发现还是出现了一样的问题。突然，这个时候好像被一棍子敲醒了，null与” "是不一样的，这时才想到上面的解决办法，先将json.get(“data”)转成字符串类型，再获取长度，判断是不是为0。

报错信息：

net.sf.json.JSONException: JSONObject[“data”] is not a JSONArray.

at net.sf.json.JSONObject.getJSONArray(JSONObject.java:1306)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at filter.EncodeFilter.doFilter(EncodeFilter.java:37)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452)

at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087)

at org.apache.coyote.AbstractProtocolAbstractConnectionHandler.process(AbstractProtocol.java:637)atorg.apache.tomcat.util.net.AprEndpointAbstractConnectionHandler.process(AbstractProtocol.java:637)atorg.apache.tomcat.util.net.AprEndpointSocketProcessor.doRun(AprEndpoint.java:2536)

at org.apache.tomcat.util.net.AprEndpointSocketProcessor.run(AprEndpoint.java:2525)atjava.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)atjava.util.concurrent.ThreadPoolExecutorSocketProcessor.run(AprEndpoint.java:2525)atjava.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)atjava.util.concurrent.ThreadPoolExecutorWorker.run(ThreadPoolExecutor.java:615)

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

at java.lang.Thread.run(Thread.java:744)