Servlet处理从表单获取字符串后返回结果。

Question

问题是这样的：

我用天气接口获取了一串JSON数据，然后这串数据解析之后只能在控制台输出。

最终想把解析后的数据放到页面上显示，以漂亮的页面展现出来。

在摸索的途中遇到问题，从JSP页面中获取了一个字符串（city），然后想把这个字符串传入相应的函数中（Getweather）返回结果。此时控制台报错：

六月 01, 2018 3:59:25 下午 org.apache.catalina.core.StandardWrapperValve invoke

严重: Servlet.service() for servlet [com.W.test2] in context with path [/Weather] threw exception [Servlet execution threw an exception] with root cause

java.lang.ClassNotFoundException: org.apache.http.conn.scheme.SchemeSocketFactory

at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1292)

at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1121)

at com.W.WeatherUtils.getWeatherData(WeatherUtils.java:46)

at com.W.WeatherUtils.<init>(WeatherUtils.java:27)

at com.W.GetWeather.<init>(GetWeather.java:16)

at com.W.test2.doGet(test2.java:24)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:494)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)

at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:651)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)

at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:407)

at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)

at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:754)

at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1376)

at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)

at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

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

at java.lang.Thread.run(Unknown Source)

页面报错：

Servlet

JSP

我用的Eclipse,xml配置文件似乎没有用过。

请问我需要怎么改才能把后台的数据输出到页面中？

Answer 1

web.xml配置你的query，有没有用你直接访问localhost:8080/query看你resp打印的内容是否正常，后台用req.setAtribute或者getsession.setAtribute的形势将你的值放进map，前台用<%xxx=request.getAtribu（你设置的map）%>