Eclipse Luna F6不會跨越

Question

奇怪的是，我在Eclipse Luna中有一個Java應用程序，當調試它時，我試圖使用F6它不會「超越」，而是「步入」。

Answer 1

我正試圖在Eclipse Luna中構建Java應用程序。這是一個來自 here的數據庫應用程序。

隨着兩個源文件（DB.java）：

`import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.sql.Statement; 

public class DB { 

public Connection conn = null; 

public DB() { 
    try { 
     Class.forName("com.mysql.jdbc.Driver"); 
     String url = "jdbc:mysql://localhost:3306/Crawler"; 
     conn = DriverManager.getConnection(url, "root", "admin213"); 
     System.out.println("conn built"); 
    } catch (SQLException e) { 
     e.printStackTrace(); 
    } catch (ClassNotFoundException e) { 
     e.printStackTrace(); 
    } 
} 

public ResultSet runSql(String sql) throws SQLException { 
    Statement sta = conn.createStatement(); 
    return sta.executeQuery(sql); 
} 

public boolean runSql2(String sql) throws SQLException { 
    Statement sta = conn.createStatement(); 
    return sta.execute(sql); 
} 

@Override 
protected void finalize() throws Throwable { 
    if (conn != null || !conn.isClosed()) { 
     conn.close(); 
    } 
} 
}` 

和Main.java：

`import java.io.IOException; 
import java.sql.PreparedStatement; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.sql.Statement; 
import org.jsoup.Jsoup; 
import org.jsoup.nodes.Document; 
import org.jsoup.nodes.Element; 
import org.jsoup.select.Elements; 


public class Main { 
    public static DB db = new DB(); 

    public static void main(String[] args) throws SQLException, IOException { 
     db.runSql2("TRUNCATE Record;"); 
     processPage("http://www.mit.edu"); 
    } 

    public static void processPage(String URL) throws SQLException, IOException{ 
     //check if the given URL is already in database 
     String sql = "select * from Record where URL = '"+URL+"'"; 
     ResultSet rs = db.runSql(sql); 
     if(rs.next()){ 

     }else{ 
      //store the URL to database to avoid parsing again 
      sql = "INSERT INTO `Crawler`.`Record` " + "(`URL`) VALUES " + "(?);"; 
      PreparedStatement stmt = db.conn.prepareStatement(sql, 
       Statement.RETURN_GENERATED_KEYS); 
      stmt.setString(1, URL); 
      stmt.execute(); 

      //get useful information 
      Document doc = Jsoup.connect("http://www.mit.edu/").get(); 

      if(doc.text().contains("research")){ 
       System.out.println(URL); 
      } 

      //get all links and recursively call the processPage method 
      Elements questions = doc.select("a[href]"); 
      for(Element link: questions){ 
       if(link.attr("href").contains("mit.edu")) 
       processPage(link.attr("abs:href")); 
      } 
     } 
    } 
}` 

忘了包括MySQL的連接器的Java-5.1.16槽。 jar進入構建路徑。 這會導致DB（） 初始化程序代碼中發生初始化時發生異常。至少這是我的假設，Eclipse的行爲是 惱火（也許它是一個功能？），並且這一步沒有正常工作。