为什么运行后就提示这样的错误：Exception in thread "main" java.lang.Error: Unresolved compilation problem:

Question

为什么运行后就提示这样的错误：Exception in thread "main" java.lang.Error: Unresolved compilation problem: 
Syntax error on token(s), misplaced construct(s) at dljm.main.Departmentmanage.<init>(Departmentmanage.java:216)
at dljm.main.Departmentmanage.main(Departmentmanage.java:296)
216行代码是这样的：public static boolean joinDB();
295，296行代码是这样的：Departmentmanage  dm = new Departmentmanage();
              dm.show();       {

Answer 1

Departmentmanage 有没有那个那个空参的构造方法？

Answer 2

因为代码太长分开了发
package dljm.main;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;public class Departmentmanage extends JFrame{ JLabel lb1 = new JLabel("部门名称");
JLabel lb2 = new JLabel("部门_ID");
JLabel lb3 = new JLabel("部门_负责人");
JLabel lb4 = new JLabel("部门_负责人_ID");
JLabel lb5= new JLabel("部门_负责人_权限");
JTextField tnumber = new JTextField();
JTextField tname = new JTextField();
JTextField tcount = new JTextField();
JButton btright = new JButton("<<");
    JButton btleft = new JButton(">>");
    JButton btdelet = new JButton("删除");
    JButton btamend = new JButton("修改");
    JButton btsave = new JButton("保存");
    JButton btadd = new JButton("添加");
    public Departmentmanage(){ setTitle("部门信息管理");
        btsave.setEnabled(false); getContentPane().setLayout(null);
Font f = new Font("新宋体",0,14);
btleft.setFont(f); lb1.setFont(new java.awt.Font("新宋体", 1, 18));
        lb1.setForeground(new Color(0, 51, 255));
        getContentPane().add(lb1);
        lb1.setBounds(110, 20, 160, 30);        lb2.setFont(f);
        getContentPane().add(lb2);
        lb2.setBounds(40, 85, 70, 20);
        lb3.setFont(f);
        getContentPane().add(lb3);
        lb3.setBounds(40, 125, 70, 20);
        lb4.setFont(f);
        getContentPane().add(lb4);
        lb4.setBounds(40,165,70,20);
        lb5.setFont(f);
        getContentPane().add(lb5);
        lb5.setBounds(40,205,70,20);        getContentPane().add(tnumber);
        tnumber.setBounds(155,85,100,23);
        getContentPane().add(tname);
        tname.setBounds(155,125,120,23);
        getContentPane().add(tcount);
        tcount.setBounds(155,165,120,23);        btright.setFont(f);
getContentPane().add(btright);
        btright.setBounds(330, 250, 50, 20);        btleft.setFont(f);
        getContentPane().add(btleft);
        btleft.setBounds(330, 230, 50, 20);
        btdelet.setFont(f);
        getContentPane().add(btdelet);
        btdelet.setBounds(250, 240, 70, 25);        btamend.setFont(f);
        getContentPane().add(btamend);
        btamend.setBounds(170, 240, 70, 25);        btsave.setFont(f);
        getContentPane().add(btsave);
        btsave.setBounds(10, 240, 70, 25);        btadd.setFont(f);
        getContentPane().add(btadd);
        btadd.setBounds(90, 240, 70, 25);
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        setBounds((screenSize.width-403)/2, (screenSize.height-329)/2, 403, 329);

Answer 3

   //连接数据库-------
        class Database {
            public static Connection cn;
            public static Statement st;
            public static ResultSet rs;
            public boolean joinDB() {
                boolean joinFlag;
                try {
                    joinFlag = true;
                    Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
                    cn = DriverManager.getConnection("jdbc:odbc:EmployeeInformationMS","sa","123456");
                    
                    cn.setCatalog("rm");
                    System.out.println("数据库连接成功");
                    st = cn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
                                            ResultSet.CONCUR_READ_ONLY);
                    return joinFlag;                } catch (SQLException sqlEx) {
                    System.out.println(sqlEx.getMessage());                    joinFlag = false;
                    return joinFlag;                } catch (ClassNotFoundException notfoundEX) {
                    System.out.println(notfoundEX.getMessage());                    joinFlag = false;
                    return joinFlag;
                }
            }            public boolean executeSQL(String sqlString) {
                boolean executeFlag;
                try {
                    st.execute(sqlString);
                    executeFlag = true;
                } catch (Exception e) {
                    executeFlag = false;
                    System.out.println("sql exception:" + e.getMessage());
                }
                return executeFlag;
            }
            public boolean query(String sqlString) {                try {
                    rs = null;
                    //System.out.println(sqlString);
                    rs = st.executeQuery(sqlString);
                } catch (Exception Ex) {
                    System.out.println("sql exception:" + Ex);
                    return false;
                }
                return true;
            }
}//-------------------------------------------------------------------//为左右按钮加事件--------------------------------------------------
     btright.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e){
      try{
      if(Database.rs.previous()){
         String number=("" + Database.rs.getInt("D_Number"));
          
            String name=Database.rs.getString("D_Name");
            String count=Database.rs.getString("D_Count");
            tnumber.setEditable(true);
            tnumber.setText(number);
            tname.setText(name);
            tcount.setText(count);
      }
        }
       catch(Exception el){
        System.out.println(el);
        }
      }
      });
     btleft.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e){
      try{
      if(Database.rs.next()){
         String number=("" + Database.rs.getInt("D_Number"));
           
            String name=Database.rs.getString("D_Name");
            String count=Database.rs.getString("D_Count");
            tnumber.setEditable(true);
            tnumber.setText(number);
            tname.setText(name);
            tcount.setText(count);
      }
        }
       catch(Exception er){
        System.out.println(er);
        }
      }
      });
//-----------------------------------------------------------------
//为添加删除保存修改按钮加事件----------------------------------------
    btadd.addActionListener(new ActionListener(){
     public void actionPerformed(ActionEvent e){
     btsave.setEnabled(true);
     tnumber.setText("");
     tnumber.setEditable(false);
         tname.setText("");
         tcount.setText("");
     }
     });
   btsave.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e){
       if(tname.getText().equals("") || tcount.getText().equals("")){
       new JOptionPane().showMessageDialog(null,"部门名和部门人数都不能为空！");
       }
       else{
       String name=tname.getText();
       String count=tcount.getText();
       String sInsert = "insert DepartmentInformation values('"+ name +"','"+ count +"')";
       try{
       if(Database.executeSQL(sInsert)){
       tnumber.setEditable(true);
       btsave.setEnabled(false);
       new JOptionPane().showMessageDialog(null,"添加数据成功！");
       public static boolean joinDB();
       {
       boolean joinFlag;
       }
       String sql="select * from bmenInfo";
       Database.query(sql);
       Database.rs.last();
           String number1=("" + Database.rs.getInt("D_Number"));
                     String name1=Database.rs.getString("D_Name");
                     String count1=Database.rs.getString("D_Count");
                     tnumber.setText(number1);
                     tname.setText(name1);
                     tcount.setText(count1);
       }       else{
       new JOptionPane().showMessageDialog(null,"添加数据不成功！");
       }
       }
       catch(Exception ei){
       new JOptionPane().showMessageDialog(null,"添加数据不成功！");
       }
       }
       }
    });    btdelet.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e){
    try{
    String sql="delete from DepartmentInformation where D_Number ='"+ tnumber.getText()+"'";
    System.out.println(sql);
    if(Database.executeSQL(sql)){
    new JOptionPane().showMessageDialog(null,"数据删除成功！");
    Database.joinDB();
       String sqll="select * from DepartmentInformation";
       Database.query(sqll);
       Database.rs.last();
           String number1=("" + Database.rs.getInt("D_Number"));
                    
                     String name1=Database.rs.getString("D_Name");
                     String count1=Database.rs.getString("D_Count");
                     tnumber.setText(number1);
                     tname.setText(name1);
                     tcount.setText(count1);
    }
    }
    catch(Exception el){}
    }
    });    btamend.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e){
    try{
    String supdate="update DepartmentInformation set D_Name='"+ tname.getText() +"',D_count='"+ tcount.getText()+"' where D_Number='"+ tnumber.getText()+"'";    if(Database.executeSQL(supdate)){
    new JOptionPane().showMessageDialog(null,"数据修改成功！");
    Database.joinDB();
       String sqll="select * from bmenInfo";
       Database.query(sqll);
       Database.rs.last();
           String number1=("" + Database.rs.getInt("D_Number"));
                    
                     String name1=Database.rs.getString("D_Name");
                     String count1=Database.rs.getString("D_Count");
                     tnumber.setText(number1);
                     tname.setText(name1);
                     tcount.setText(count1);
    }
    }
    catch(Exception es){}
    }
    });
  //-----------------------------------------------------------------
    this.setClosable(true);
    setVisible(true);}
public static void main(String[] args){ Departmentmanage  dm = new Departmentmanage();
dm.show();
}
}

Answer 4

哥们，你的代码能编译吗？
我怎么编译都不过
public static boolean joinDB();
{
 boolean joinFlag;
}
这个是什么东西？
干什么用的？
是谁的方法阿？
没看懂

Answer 5

jdbc:odbc:EmployeeInformationMS这个是你的url还是什么？

Answer 6

改了一下，能运行了，其他的再测测吧，不知道你考代码还是什么其他原因，编译都不通过
-----------------------------------------------------------------
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;public class Departmentmanage extends JFrame {    JLabel lb1 = new JLabel("部门名称");    JLabel lb2 = new JLabel("部门_ID");    JLabel lb3 = new JLabel("部门_负责人");    JLabel lb4 = new JLabel("部门_负责人_ID");    JLabel lb5 = new JLabel("部门_负责人_权限");    JTextField tnumber = new JTextField();    JTextField tname = new JTextField();    JTextField tcount = new JTextField();    JButton btright = new JButton(" < <");    JButton btleft = new JButton(">>");    JButton btdelet = new JButton("删除");    JButton btamend = new JButton("修改");    JButton btsave = new JButton("保存");    JButton btadd = new JButton("添加");    public Departmentmanage() {        setTitle("部门信息管理");
        btsave.setEnabled(false);        getContentPane().setLayout(null);
        Font f = new Font("新宋体", 0, 14);
        btleft.setFont(f);        lb1.setFont(new java.awt.Font("新宋体", 1, 18));
        lb1.setForeground(new Color(0, 51, 255));
        getContentPane().add(lb1);
        lb1.setBounds(110, 20, 160, 30);        lb2.setFont(f);
        getContentPane().add(lb2);
        lb2.setBounds(40, 85, 70, 20);
        lb3.setFont(f);
        getContentPane().add(lb3);
        lb3.setBounds(40, 125, 70, 20);
        lb4.setFont(f);
        getContentPane().add(lb4);
        lb4.setBounds(40, 165, 70, 20);
        lb5.setFont(f);
        getContentPane().add(lb5);
        lb5.setBounds(40, 205, 70, 20);        getContentPane().add(tnumber);
        tnumber.setBounds(155, 85, 100, 23);
        getContentPane().add(tname);
        tname.setBounds(155, 125, 120, 23);
        getContentPane().add(tcount);
        tcount.setBounds(155, 165, 120, 23);        btright.setFont(f);
        getContentPane().add(btright);
        btright.setBounds(330, 250, 50, 20);        btleft.setFont(f);
        getContentPane().add(btleft);
        btleft.setBounds(330, 230, 50, 20);        btdelet.setFont(f);
        getContentPane().add(btdelet);
        btdelet.setBounds(250, 240, 70, 25);        btamend.setFont(f);
        getContentPane().add(btamend);
        btamend.setBounds(170, 240, 70, 25);        btsave.setFont(f);
        getContentPane().add(btsave);
        btsave.setBounds(10, 240, 70, 25);        btadd.setFont(f);
        getContentPane().add(btadd);
        btadd.setBounds(90, 240, 70, 25);
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        setBounds((screenSize.width - 403) / 2, (screenSize.height - 329) / 2, 403, 329);        // -------------------------------------------------------------------        // 为左右按钮加事件--------------------------------------------------
        btright.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try {
                    if (Database.rs.previous()) {
                        String number = ("" + Database.rs.getInt("D_Number"));                        String name = Database.rs.getString("D_Name");
                        String count = Database.rs.getString("D_Count");
                        tnumber.setEditable(true);
                        tnumber.setText(number);
                        tname.setText(name);
                        tcount.setText(count);
                    }
                } catch (Exception el) {
                    System.out.println(el);
                }
            }
        });        btleft.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try {
                    if (Database.rs.next()) {
                        String number = ("" + Database.rs.getInt("D_Number"));                        String name = Database.rs.getString("D_Name");
                        String count = Database.rs.getString("D_Count");
                        tnumber.setEditable(true);
                        tnumber.setText(number);
                        tname.setText(name);
                        tcount.setText(count);
                    }
                } catch (Exception er) {
                    System.out.println(er);
                }
            }
        });        // -----------------------------------------------------------------        // 为添加删除保存修改按钮加事件----------------------------------------
        btadd.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                btsave.setEnabled(true);
                tnumber.setText("");
                tnumber.setEditable(false);
                tname.setText("");
                tcount.setText("");
            }
        });
        btsave.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                if (tname.getText().equals("") || tcount.getText().equals("")) {
                    new JOptionPane().showMessageDialog(null, "部门名和部门人数都不能为空！");
                } else {
                    String name = tname.getText();
                    String count = tcount.getText();
                    String sInsert =
                            "insert DepartmentInformation values('" + name + "','" + count + "')";
                    try {
                        if (Database.executeSQL(sInsert)) {
                            tnumber.setEditable(true);
                            btsave.setEnabled(false);
                            new JOptionPane().showMessageDialog(null, "添加数据成功！");
                            // public static boolean joinDB();
                            // {
                            // boolean joinFlag;
                            // }
                            String sql = "select * from bmenInfo";
                            Database.query(sql);
                            Database.rs.last();
                            String number1 = ("" + Database.rs.getInt("D_Number"));
                            String name1 = Database.rs.getString("D_Name");
                            String count1 = Database.rs.getString("D_Count");
                            tnumber.setText(number1);
                            tname.setText(name1);
                            tcount.setText(count1);
                        }                        else {
                            new JOptionPane().showMessageDialog(null, "添加数据不成功！");
                        }
                    } catch (Exception ei) {
                        new JOptionPane().showMessageDialog(null, "添加数据不成功！");
                    }
                }
            }
        });        

Answer 7

btdelet.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try {
                    String sql =
                            "delete from DepartmentInformation where D_Number ='"
                                + tnumber.getText()
                                + "'";
                    System.out.println(sql);
                    if (Database.executeSQL(sql)) {
                        new JOptionPane().showMessageDialog(null, "数据删除成功！");
                        Database.joinDB();
                        String sqll = "select * from DepartmentInformation";
                        Database.query(sqll);
                        Database.rs.last();
                        String number1 = ("" + Database.rs.getInt("D_Number"));                        String name1 = Database.rs.getString("D_Name");
                        String count1 = Database.rs.getString("D_Count");
                        tnumber.setText(number1);
                        tname.setText(name1);
                        tcount.setText(count1);
                    }
                } catch (Exception el) {
                }
            }
        });        btamend.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try {
                    String supdate =
                            "update DepartmentInformation set D_Name='"
                                + tname.getText()
                                + "',D_count='"
                                + tcount.getText()
                                + "' where D_Number='"
                                + tnumber.getText()
                                + "'";                    if (Database.executeSQL(supdate)) {
                        new JOptionPane().showMessageDialog(null, "数据修改成功！");
                        Database.joinDB();
                        String sqll = "select * from bmenInfo";
                        Database.query(sqll);
                        Database.rs.last();
                        String number1 = ("" + Database.rs.getInt("D_Number"));                        String name1 = Database.rs.getString("D_Name");
                        String count1 = Database.rs.getString("D_Count");
                        tnumber.setText(number1);
                        tname.setText(name1);
                        tcount.setText(count1);
                    }
                } catch (Exception es) {
                }
            }
        });
        // -----------------------------------------------------------------
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);    }    public static void main(String[] args) {        Departmentmanage dm = new Departmentmanage();
        dm.show();
    }    static class Database {
        public static Connection cn;        public static Statement st;        public static ResultSet rs;        public static boolean joinDB() {
            boolean joinFlag;
            try {
                joinFlag = true;
                Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
                cn = DriverManager.getConnection("jdbc:odbc:EmployeeInformationMS", "sa", "123456");                cn.setCatalog("rm");
                System.out.println("数据库连接成功");
                st =
                        cn.createStatement(
                            ResultSet.TYPE_SCROLL_SENSITIVE,
                            ResultSet.CONCUR_READ_ONLY);
                return joinFlag;            } catch (SQLException sqlEx) {
                System.out.println(sqlEx.getMessage());                joinFlag = false;
                return joinFlag;            } catch (ClassNotFoundException notfoundEX) {
                System.out.println(notfoundEX.getMessage());                joinFlag = false;
                return joinFlag;
            }
        }        public static boolean executeSQL(String sqlString) {
            boolean executeFlag;
            try {
                st.execute(sqlString);
                executeFlag = true;
            } catch (Exception e) {
                executeFlag = false;
                System.out.println("sql exception:" + e.getMessage());
            }
            return executeFlag;
        }        public static boolean query(String sqlString) {            try {
                rs = null;
                // System.out.println(sqlString);
                rs = st.executeQuery(sqlString);
            } catch (Exception Ex) {
                System.out.println("sql exception:" + Ex);
                return false;
            }
            return true;
        }
    }
}

Answer 8

7楼的朋友如果将代码改成你说的那样就提示这样的错误：java.lang.NoSuchMethodError: main
Exception in thread "main"