春季启动运行但独立的tomcat无法正常工作

Question

我正在开发一个 Spring Boot Web 应用程序（我的第一个应用程序），当我将它部署在嵌入式 tomcat 服务器中时它工作正常。但是当我将它部署在独立 Tomcat 服务器中时，它无法访问数据库。我正在使用 Rest WebService 将数据传递到前端，我的 url 看起来像

http://localhost:8080/day_demand?day=3

但是当我访问时在我的独立服务器中 http://localhost:8080/WebApp/day_demand?day=3（WebApp是我的项目名）

通过以下代码连接数据库：

private Connection connectToDatabaseOrDie()
  {
    Connection conn = null;
    try
    {
      Class.forName("org.postgresql.Driver");
      String url = "jdbc:postgresql://localhost:5432/data_base";
      conn = DriverManager.getConnection(url,"user", "password");
    }
    catch (ClassNotFoundException e)
    {
      e.printStackTrace();
      System.exit(1);
    }
    catch (SQLException e)
    {
      e.printStackTrace();
      System.exit(2);
    }
    return conn;
  }
private void populateListOfTopics(Connection conn, List<State> listOfBlogs,Timestamp start_time,Timestamp end_time,int zone_id)
  {
    try 
    {

        String sql= "SELECT * FROM public.table where time >= ? and time <= ?";
        PreparedStatement pstmt = conn.prepareStatement(sql);
        pstmt.setTimestamp(1,start_time);


        pstmt.setTimestamp(2,end_time);


        ResultSet rs = pstmt.executeQuery();


      while ( rs.next() )
      {
          State blog = new State();

        blog.year = rs.getInt ("year");
        blog.month=rs.getInt ("month");
        blog.day  = rs.getInt ("day");
        blog.hour = rs.getInt ("hour");



        listOfBlogs.add(blog);
      }

      rs.close();
      pstmt.close();
      conn.close();
    }
    catch (SQLException se) {
      System.err.println("Threw a SQLException creating the list of state.");
      System.err.println(se.getMessage());
    } catch (Exception e) {
        System.out.println("Err");
        e.printStackTrace();
    }
  }

我无法访问数据。感谢任何帮助。

Answer 1

您需要执行以下步骤：

1) In pom.xml file , make scope as provided for embedded server 

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-undertow</artifactId>
          <scope>provided</scope>
    </dependency>

     or

 <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
 </dependency>

 2) In pom.xml file, make packaging as war

     <packaging>war</packaging>

 3)  Extend SpringBootServletInitializer class in your Application.class


            import org.springframework.boot.SpringApplication;
            import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
            import org.springframework.boot.autoconfigure.SpringBootApplication;
            import org.springframework.boot.builder.SpringApplicationBuilder;
            import org.springframework.boot.context.web.SpringBootServletInitializer;
            import org.springframework.context.annotation.ComponentScan;
            import org.springframework.context.annotation.Configuration;


            @SpringBootApplication
            @Configuration
            @ComponentScan
            @EnableAutoConfiguration

            public class Application extends SpringBootServletInitializer{



               public static void main(String[] args) {
                  SpringApplication.run(Application.class, args);
               }

               @Override
               protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
                   return application.sources(Application.class);
               }

               private static Class<Application> applicationClass = Application.class;

            }



 4) Take  the war from target folder and deploy it to External tomcat 
  and start the server.You will see logs as below :

5) 点击如下所示的 URL：

http://localhost:8080/SpringBootExamples-0.0.1-SNAPSHOT/persons/1

SpringBootExamples-0.0.1-SNAPSHOT = 上下文路径

与外部 Tomcat 服务器中提取的文件夹名称相同

Answer 2

@约翰

我已经根据我的数据库扭曲了你的代码，并且我能够从 db.Im 使用 mysql 获取数据。

代码如下：

                @RestController
                public class PersonController {



                    @Autowired
                    private PersonRepository personRepository;

                    @RequestMapping(value = "/persons/{id}", method = RequestMethod.GET,produces={MediaType.APPLICATION_XML_VALUE},headers = "Accept=application/xml")
                    public ResponseEntity<?> getPersonDetails(@PathVariable Long id, final HttpServletRequest request)throws Exception {
                        System.out.println("Before");
                        ConnectionManager cm=new ConnectionManager();
                        Person personResponse=cm.populateListOfTopics();
                        System.out.println("personResponse"+personResponse);
                        return ResponseEntity.ok(personResponse);
                    }

                }

连接类：

                    import java.sql.Connection;
                    import java.sql.DriverManager;
                    import java.sql.PreparedStatement;
                    import java.sql.ResultSet;
                    import java.sql.SQLException;
                    import java.sql.Timestamp;
                    import java.util.List;

                    public class ConnectionManager {

                    private Connection connectToDatabaseOrDie()
                      {
                        Connection conn = null;
                        try
                        {
                          Class.forName("com.mysql.jdbc.Driver");
                          String url = "jdbc:mysql://localhost:3306/master?createDatabaseIfNotExist=false";
                          conn = DriverManager.getConnection(url,"root", "mysql");
                        }
                        catch (ClassNotFoundException e)
                        {
                          e.printStackTrace();
                          System.exit(1);
                        }
                        catch (SQLException e)
                        {
                          e.printStackTrace();
                          System.exit(2);
                        }
                        return conn;
                      }

                    public Person populateListOfTopics()
                      {
                         Person person=new Person();
                        try 
                        {
                            Connection conn = ConnectionManager.this.connectToDatabaseOrDie();
                            String sql= "SELECT *  FROM master.person WHERE ID = 1";
                            PreparedStatement pstmt = conn.prepareStatement(sql);
                            ResultSet rs = pstmt.executeQuery();

                          while (rs.next())
                          {
                            person.setFirst_name(rs.getString("FIRST_NAME"));

                          }

                          rs.close();
                          pstmt.close();
                          conn.close();
                        }
                        catch (SQLException se) {
                          System.err.println("Threw a SQLException creating the list of state.");
                          System.err.println(se.getMessage());
                        } catch (Exception e) {
                            System.out.println("Err");
                            e.printStackTrace();
                        }

                        return person;
                      }


                    }