我试图让Java中的本地JSON文件的内容。相反,我正在以下堆栈跟踪:
java.lang.NullPointerException
fi.avaliaho.ottoautomaatitv2.Webservice.doGet(Webservice.java:24)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
org.apache.catalina.filters.CorsFilter.handleNonCORS(CorsFilter.java:352)
org.apache.catalina.filters.CorsFilter.doFilter(CorsFilter.java:171)
我已经确信该文件coordinates.json
位于同一目录Webservice.java
文件。我知道this question的,但答案没有解决我的问题。这里是我的servlet:
import java.net.URL;
import java.io.*;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Webservice extends HttpServlet {
URL path = null;
Reader file = null;
BufferedReader input = null;
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
path = Webservice.class.getResource("coordinates.json");
file = new FileReader(path.getFile());
}
}
尝试使用getSystemResource()
方法
path = ClassLoader.getSystemResource("coordinates.json")
或者它如何被@LaksithaRanasingha在评论中提到添加qazxsw POI的开头:
/
这也可能是有用的path = Webservice.class.getResource("/coordinates.json");