SearchServlet 已由更新版本的 Java Runtime 编译

SearchServlet has been compiled by a more recent version of the Java Runtime

提问by Kyle

When I use my search feature, I get an http status 500 error. It claims that

当我使用我的搜索功能时，我收到一个 http 状态 500 错误。它声称

Error Report

HTTP Status 500 – Internal Server Error

Type Exception Report

Message SearchServlet has been compiled by a more recent version of the Java Runtime (class file version 53.0), this version of the Java Runtime only recognizes class file versions up to 52.0 (unable to load class [SearchServlet])

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception java.lang.UnsupportedClassVersionError: SearchServlet has been compiled by a more recent version of the Java Runtime (class file version 53.0), this version of the Java Runtime only recognizes class file versions up to 52.0 (unable to load class [SearchServlet]) org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2286) org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:811) org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1260) org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:488) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459) org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) java.lang.Thread.run(Unknown Source)

错误报告

HTTP 状态 500 – 内部服务器错误

类型异常报告

Message SearchServlet 已由更新版本的 Java Runtime（类文件版本 53.0）编译，此版本的 Java Runtime 仅识别最高 52.0 的类文件版本（无法加载类 [SearchServlet]）

说明 服务器遇到了阻止其完成请求的意外情况。

异常 java.lang.UnsupportedClassVersionError: SearchServlet 已由更新版本的 Java Runtime（类文件版本 53.0）编译，此版本的 Java Runtime 仅识别最高 52.0 的类文件版本（无法加载类 [SearchServlet]） org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2286) org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:811) org.apache.catalina.loader.WebappClassLoaderBase.loadBase(WebappClassLoader) java:1260) org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:488) org.apache.catalina.valves.ErrorReportValve.调用（ErrorReportValve.java:81）org.apache。catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun( NioEndpoint.java:1459) org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) java.util.concurrent.ThreadPoolExecutor$Worker.run （来源不明）org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) java.lang.Thread.run（来源不明）运行（未知来源）

I am using compiler compliance level 9. I have JRE 1.8 which I thought was the most recent. When I try to install Java 9, using the Eclipse Marketplace, it tells me that

我正在使用编译器合规性级别 9。我有 JRE 1.8，我认为它是最新的。当我尝试使用 Eclipse Marketplace 安装 Java 9 时，它告诉我

No repository found at http://download.eclipse.org/eclipse/updates/none.

在以下位置找不到存储库 http://download.eclipse.org/eclipse/updates/none.

I believe, given all of this, I am completely up to date, but how am I not able to search for records in the database?

我相信，鉴于所有这些，我完全是最新的，但是我怎么不能在数据库中搜索记录？

<!DOCTYPE html>
<html>

<head>
  <meta charset="ISO-8859-1" <title>Add contact to Phone Book</title>
  <h1>Add contact to Phone Book</h1>
</head>

<body>
  <form name="submitInfo" method="get" action="AddEntryServlet" First Name: <input type="text" name="firstName" />
  <br/>
  <br/>
   Last Name: <input type="text" name="lastName" />
  <br/>
  <br/>
   Area Code: <input type="number" name="areaCode" />
  <br/>
  <br/>
   Phone Number: <input type="number" name="phoneNumber" />
  <br/>
  <br/>
  <input type="submit" value="Submit" />

  </form>
</body>
<h1>Search for Contact in Phone Book</h1>

<body>
  <form name="searchInfo" method="get" action="SearchServlet">
    Search First Name: <input type="text" name="searchFirstName" />
    <br/>
    <br/>

    <input type="submit" name="action" value="search" />

  </form>
</body>

</html> 

Search servlet code

搜索 servlet 代码

import java.io.IOException; 
import java.io.PrintWriter; 
import java.util.List;

import javax.servlet.ServletException; 
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.hibernate.Query; import org.hibernate.Session;

import entities.Tbphonebook; import util.HibernateUtil;

/**  * Servlet implementation class SearchServlet  */
@SuppressWarnings("deprecation")
@WebServlet("/SearchServlet")
public class SearchServlet extends HttpServlet {    private static final long
serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public SearchServlet() {
super();
  // TODO Auto-generated constructor stub
  }

/**      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)      */
@SuppressWarnings({ "deprecation","unchecked" })
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    Session session = HibernateUtil.getSessionFactory().openSession();
    session.beginTransaction();
    String firstName = request.getParameter("searchFirstName");         
    @SuppressWarnings("rawtypes") 
    Query query = Session.createQuery("from Tbphonebook where firstname = ?");


List<Tbphonebook> persons = (List<Tbphonebook>) query.getResultList();



session.getTransaction().commit();      
session.close();



request.setAttribute("persons", persons);
request.getRequestDispatcher("searchResults.jsp").forward(request,response);
response.sendRedirect("searchResults.jsp");


}

Results jsp

结果jsp

%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1"> <title>Insert title here</title> </head>
<h1>Search Results</h1>
<h1>List Books:</h1>
<table class="table table-boardered table-striped" id="searchresults">      
    <tr>            
        <th>First Name</th>         
        <th>Last Name</th>
        <th>Area Code</th>          
        <th>PhoneNumber</th>
    </tr>       
</table>
<script>
        $(document).ready(function(){
        $.getJSON("persons", function(data){
            var persons_data = '';
            $.each(data, function(key, value){
                person_date += '<tr>';
                person_data += '<td>'+value.Firstname+'</td>';
                person_data += '<td>'+value.Lastname+'</td>';
                person_data += '<td>'+value.Areacode+'</td>';
                person_data += '<td>'+value.Phonenumber+'</td>';
                person_date += '</tr>';
            }
            );
        $('#searchresults').append(persons_data);
        });
    });
 </script>
<%
    String message = (String) request.getAttribute("message");
    if(!(message == null)){
        out.println(message);
        }else{
            message= "";
            out.println(message);
        }
%>

 </html>

采纳答案by Steve11235

"When I go to my compiler I am using compiler compliance level 9." Version 52.0 is Java 8; I assume 53.0 is Java 9. You are attempting to run code compiled for Java 9 on Java 8, which results in the error you are getting. Change your compliance version to Java 8.

“当我使用编译器时，我使用的是编译器合规性级别 9。” 版本 52.0 是 Java 8；我假设 53.0 是 Java 9。您试图在 Java 8 上运行为 Java 9 编译的代码，这会导致您遇到错误。将您的合规版本更改为 Java 8。

回答by Eric D

IDE: Eclipse Oxygen.

IDE：日食氧气。

To temporarily correct the problem do the following:

要暂时更正问题，请执行以下操作：

Project menu> Properties> Java Compiler> Compiler compliance level> 1.8

Project menu> Properties> Java Compiler> Compiler compliance level>1.8

A permanent fix likely involves installing JDK 9.

永久性修复可能涉及安装 JDK 9。

FYI 1.8 is what Java 8 is called.

仅供参考 1.8 就是 Java 8 的名称。

Side bar

侧边栏

I recently returned to Java after a foray into C# and installed Eclipse Oxygen onto a clean system that had never had Java installed on it before. This default everythingwith a brand new install of Eclipse Oxygen yet somehow or other Eclipse can't get its own parameters to match the jdk that's installed. This is the second project I created and the second time I ran into this headache.

我最近在尝试 C# 后回到 Java，并将 Eclipse Oxygen 安装到一个干净的系统上，该系统以前从未安装过 Java。这种默认的一切都与一个全新的安装Eclipse氧但不知何故或其他Eclipse不能让自己的参数匹配的已安装了JDK。这是我创建的第二个项目，也是我第二次遇到这种头痛。

回答by Oleksii Kyslytsyn

1) If you are compiling using maven plugin: try configuring your version explicitly, for example:

1) 如果您使用 maven 插件进行编译：尝试明确配置您的版本，例如：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.7.0</version>
    <configuration>
        <source>1.8</source>
        <target>1.8</target>
    </configuration>
</plugin>

2) If you are compiling using automated UNIX-like OS-script, try export configuration, for example:

2) 如果您使用自动化的类 UNIX 操作系统脚本进行编译，请尝试导出配置，例如：

export JAVA_HOME=`/usr/libexec/java_home -v 1.8`

3) If you are compiling using eclipse, try specifying JRE, for example:

3）如果你是用eclipse编译的，试试指定JRE，例如：

Compiling to a specific JRE with Eclipse

使用 Eclipse 编译为特定的 JRE

4) If you are compiling using NetBeans, try specifying JRE, for example:

4) 如果您使用 NetBeans 进行编译，请尝试指定 JRE，例如：

Netbeans - Build targetting JDK 6 but run using Java 7 JRE

Netbeans - 构建目标为 JDK 6 但使用 Java 7 JRE 运行