求大神帮忙~ applet 不需要main方法的,你在eclipse中直接 run as java applet 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 你的applet程序是可以运行的,这个不用main方法作入口的,不过现在很少有人用这个了。 package test;import java.applet.Applet;import java.awt.Button;import java.awt.GridLayout;import java.awt.Label;import java.awt.TextField;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.util.Vector;public class Students extends Applet implements ActionListener { /** * */ private static final long serialVersionUID = 1230599364611081671L; @SuppressWarnings("rawtypes") Vector StuInf = new Vector(); StudentInf SI; String xm; String bj; int i, j, xh, cj; static int mid; Label prompt1 = new Label("学生成绩管理系统"); Label prompt2 = new Label(" 用户:"); Label prompt3 = new Label(" 密码:"); Label prompt4 = new Label(" 班级:"); Label prompt5 = new Label(" 成绩:"); TextField input1 = new TextField(8); TextField input2 = new TextField(8); TextField input3 = new TextField(8); TextField input4 = new TextField(8); Button btn1 = new Button("登录"); Button btn2 = new Button("增加"); Button btn3 = new Button("修改"); Button btn4 = new Button("删除"); public void init() { setLayout(new GridLayout(6, 3)); add(new Label()); add(prompt1); add(new Label()); add(prompt2); add(input1); add(new Label()); add(prompt3); add(input2); add(btn1); add(prompt4); add(input3); add(new Label()); add(prompt5); add(input4); add(new Label()); add(btn2); add(btn3); add(btn4); prompt4.setVisible(false); prompt5.setVisible(false); input3.setVisible(false); input4.setVisible(false); btn2.setVisible(false); btn3.setVisible(false); btn4.setVisible(false); btn1.addActionListener(this); btn2.addActionListener(this); btn3.addActionListener(this); btn4.addActionListener(this); } public static void main(String[] args) { new Students(); } @SuppressWarnings("unchecked") public void actionPerformed(ActionEvent e) { if (e.getActionCommand() == "登录") { String a, b; a = input1.getText(); b = input2.getText(); input1.setText(""); if ((a.equals("12") == true) && (b.equals("12") == true)) { prompt2.setText(" 姓名:"); prompt3.setText(" 学号:"); prompt4.setVisible(true); prompt5.setVisible(true); input3.setVisible(true); input4.setVisible(true); btn2.setVisible(true); btn3.setVisible(true); btn4.setVisible(true); btn3.setEnabled(false); btn4.setEnabled(false); btn1.setLabel("查询"); input1.setText("登录成功"); input1.selectAll(); } else input2.setText("用户名或密码错"); } if (e.getActionCommand() == "增加") { boolean scucss = true; try { XingMing(); } catch (EmptyException as) { input1.setText("姓名不能为空"); scucss = false; } try { xh = Integer.parseInt(input2.getText()); } catch (NumberFormatException m) { input2.setText("学号为空或格式错"); scucss = false; } bj = input3.getText(); try { ChengJi(); } catch (EmptyException as) { cj = -1; } catch (OverException dd) { input4.setText("应在0-100间"); scucss = false; } catch (NumberFormatException cm) { input4.setText("成绩应为数据"); scucss = false; } if (scucss == true) { SI = new StudentInf(xm, xh, bj, cj); Insert(SI); } } if (e.getActionCommand() == "修改") { xm = input1.getText(); xh = Integer.parseInt(input2.getText()); bj = input3.getText(); cj = Integer.parseInt(input4.getText()); SI = new StudentInf(xm, xh, bj, cj); StuInf.setElementAt(SI, mid); btn3.setEnabled(false); } if (e.getActionCommand() == "删除") { StuInf.removeElementAt(mid); btn4.setEnabled(false); input1.setText("删除成功"); input2.setText(""); input3.setText(""); input4.setText(""); } if (e.getActionCommand() == "查询") { boolean right = true; try { xh = Integer.parseInt(input2.getText()); } catch (NumberFormatException m) { input2.setText("学号为空或格式错"); right = false; } if (right == true) { search(xh); btn3.setEnabled(true); btn4.setEnabled(true); } } } // 查找方法 public void search(int k) { boolean exist = false; int low = 0; int high = StuInf.size() - 1; while (low <= high) { mid = (high + low) / 2; StudentInf a1 = (StudentInf) StuInf.elementAt(mid); if (a1.getStuNo() == k) { SI = (StudentInf) StuInf.elementAt(mid); String x = String.valueOf(SI.getStuNo()); exist = true; input1.setText(SI.getname()); input1.selectAll(); input2.setText("0" + x); input3.setText(SI.getClassNo()); if (SI.getLevel() == -1) input4.setText("未参加考试"); else { String y = String.valueOf(SI.getLevel()); input4.setText(y); } break; } else if (a1.getStuNo() < k) low = mid + 1; else high = mid - 1; } if (exist == false) { input1.setText("无此学号学生信息"); input1.selectAll(); } } // 添加方法 @SuppressWarnings("unchecked") public void Insert(StudentInf q) { int i = 0; if (StuInf.isEmpty() == true) { StuInf.addElement(q); input1.setText(""); input2.setText(""); input3.setText(""); input4.setText(""); } else { StudentInf xh; xh = (StudentInf) StuInf.firstElement(); while (xh.getStuNo() < q.getStuNo()) { i++; if (i < StuInf.size()) xh = (StudentInf) StuInf.elementAt(i); else break; } if (xh.getStuNo() == q.getStuNo()) { input2.setText("此学生信息已存在"); input2.requestFocus(); input2.selectAll(); } else { StuInf.insertElementAt(q, i); input1.setText(""); input2.setText(""); input3.setText(""); input4.setText(""); } } } // 异常类 @SuppressWarnings("serial") class OverException extends Exception { String over; } @SuppressWarnings("serial") class EmptyException extends Exception { String empty; } void XingMing() throws EmptyException { if ((input1.getText()).equals("")) throw (new EmptyException()); else xm = input1.getText(); } void ChengJi() throws OverException, EmptyException { if ((input4.getText()).equals("")) throw (new EmptyException()); else cj = Integer.parseInt(input4.getText()); if (cj < 0 || cj > 100) throw (new OverException()); } // 学生信息类 /*public 去掉public*/ class StudentInf { private String name; private int StuNo; private String ClassNo; private int Level; StudentInf(String xingming, int xuehao, String banji, int chengji) { name = xingming; StuNo = xuehao; ClassNo = banji; Level = chengji; } public int getStuNo() { return StuNo; } public String getname() { return name; } public String getClassNo() { return ClassNo; } public int getLevel() { return Level; } }}http://chuantu.biz/t/60/1420545595x1822611422.bmp synchronized的问题 关于线程的问题 java编码问题 有2个简单问题,请大家帮忙~~~ 问个读文本文件的问题 请教:ftp服务器下载文件抛出异常501 PORT not allowed after EPSV ALL 编码新发现 (SOS)为什么得到null值,有什么办法解决 我该怎么办 虚拟主机把25端口封了,java还能发送邮件吗 计算器xml中Button上的黄色感叹号如何让去除 为毛没人回复我呢
import java.awt.Button;
import java.awt.GridLayout;
import java.awt.Label;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Vector;public class Students extends Applet implements ActionListener {
/**
*
*/
private static final long serialVersionUID = 1230599364611081671L;
@SuppressWarnings("rawtypes")
Vector StuInf = new Vector();
StudentInf SI;
String xm;
String bj;
int i, j, xh, cj;
static int mid;
Label prompt1 = new Label("学生成绩管理系统");
Label prompt2 = new Label(" 用户:");
Label prompt3 = new Label(" 密码:");
Label prompt4 = new Label(" 班级:");
Label prompt5 = new Label(" 成绩:");
TextField input1 = new TextField(8);
TextField input2 = new TextField(8);
TextField input3 = new TextField(8);
TextField input4 = new TextField(8);
Button btn1 = new Button("登录");
Button btn2 = new Button("增加");
Button btn3 = new Button("修改");
Button btn4 = new Button("删除"); public void init() {
setLayout(new GridLayout(6, 3));
add(new Label());
add(prompt1);
add(new Label());
add(prompt2);
add(input1);
add(new Label());
add(prompt3);
add(input2);
add(btn1);
add(prompt4);
add(input3);
add(new Label());
add(prompt5);
add(input4);
add(new Label());
add(btn2);
add(btn3);
add(btn4);
prompt4.setVisible(false);
prompt5.setVisible(false);
input3.setVisible(false);
input4.setVisible(false);
btn2.setVisible(false);
btn3.setVisible(false);
btn4.setVisible(false);
btn1.addActionListener(this);
btn2.addActionListener(this);
btn3.addActionListener(this);
btn4.addActionListener(this);
}
public static void main(String[] args) {
new Students();
}
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand() == "登录") {
String a, b;
a = input1.getText();
b = input2.getText();
input1.setText("");
if ((a.equals("12") == true) && (b.equals("12") == true)) {
prompt2.setText(" 姓名:");
prompt3.setText(" 学号:");
prompt4.setVisible(true);
prompt5.setVisible(true);
input3.setVisible(true);
input4.setVisible(true);
btn2.setVisible(true);
btn3.setVisible(true);
btn4.setVisible(true);
btn3.setEnabled(false);
btn4.setEnabled(false);
btn1.setLabel("查询");
input1.setText("登录成功");
input1.selectAll();
} else
input2.setText("用户名或密码错");
}
if (e.getActionCommand() == "增加") {
boolean scucss = true;
try {
XingMing();
} catch (EmptyException as) {
input1.setText("姓名不能为空");
scucss = false;
}
try {
xh = Integer.parseInt(input2.getText());
} catch (NumberFormatException m) {
input2.setText("学号为空或格式错");
scucss = false;
}
bj = input3.getText();
try {
ChengJi();
} catch (EmptyException as) {
cj = -1;
} catch (OverException dd) {
input4.setText("应在0-100间");
scucss = false;
} catch (NumberFormatException cm) {
input4.setText("成绩应为数据");
scucss = false;
}
if (scucss == true) {
SI = new StudentInf(xm, xh, bj, cj);
Insert(SI);
}
}
if (e.getActionCommand() == "修改") {
xm = input1.getText();
xh = Integer.parseInt(input2.getText());
bj = input3.getText();
cj = Integer.parseInt(input4.getText());
SI = new StudentInf(xm, xh, bj, cj);
StuInf.setElementAt(SI, mid);
btn3.setEnabled(false);
}
if (e.getActionCommand() == "删除") {
StuInf.removeElementAt(mid);
btn4.setEnabled(false);
input1.setText("删除成功");
input2.setText("");
input3.setText("");
input4.setText("");
}
if (e.getActionCommand() == "查询") {
boolean right = true;
try {
xh = Integer.parseInt(input2.getText());
} catch (NumberFormatException m) {
input2.setText("学号为空或格式错");
right = false;
}
if (right == true) {
search(xh);
btn3.setEnabled(true);
btn4.setEnabled(true);
}
} } // 查找方法
public void search(int k) {
boolean exist = false;
int low = 0;
int high = StuInf.size() - 1;
while (low <= high) {
mid = (high + low) / 2;
StudentInf a1 = (StudentInf) StuInf.elementAt(mid);
if (a1.getStuNo() == k) {
SI = (StudentInf) StuInf.elementAt(mid);
String x = String.valueOf(SI.getStuNo());
exist = true;
input1.setText(SI.getname());
input1.selectAll();
input2.setText("0" + x);
input3.setText(SI.getClassNo());
if (SI.getLevel() == -1)
input4.setText("未参加考试");
else {
String y = String.valueOf(SI.getLevel());
input4.setText(y);
}
break;
} else if (a1.getStuNo() < k)
low = mid + 1;
else
high = mid - 1;
}
if (exist == false) {
input1.setText("无此学号学生信息");
input1.selectAll();
}
} // 添加方法
@SuppressWarnings("unchecked")
public void Insert(StudentInf q) {
int i = 0; if (StuInf.isEmpty() == true) {
StuInf.addElement(q);
input1.setText("");
input2.setText("");
input3.setText("");
input4.setText("");
} else {
StudentInf xh;
xh = (StudentInf) StuInf.firstElement();
while (xh.getStuNo() < q.getStuNo()) {
i++;
if (i < StuInf.size())
xh = (StudentInf) StuInf.elementAt(i);
else
break;
}
if (xh.getStuNo() == q.getStuNo()) {
input2.setText("此学生信息已存在");
input2.requestFocus();
input2.selectAll();
} else {
StuInf.insertElementAt(q, i);
input1.setText("");
input2.setText("");
input3.setText("");
input4.setText("");
}
}
} // 异常类
@SuppressWarnings("serial")
class OverException extends Exception {
String over;
} @SuppressWarnings("serial")
class EmptyException extends Exception {
String empty;
} void XingMing() throws EmptyException {
if ((input1.getText()).equals(""))
throw (new EmptyException());
else
xm = input1.getText();
} void ChengJi() throws OverException, EmptyException {
if ((input4.getText()).equals(""))
throw (new EmptyException());
else
cj = Integer.parseInt(input4.getText());
if (cj < 0 || cj > 100)
throw (new OverException());
} // 学生信息类
/*public 去掉public*/ class StudentInf {
private String name;
private int StuNo;
private String ClassNo;
private int Level; StudentInf(String xingming, int xuehao, String banji, int chengji) {
name = xingming;
StuNo = xuehao;
ClassNo = banji;
Level = chengji;
} public int getStuNo() {
return StuNo;
} public String getname() {
return name;
} public String getClassNo() {
return ClassNo;
} public int getLevel() {
return Level;
}
}}
http://chuantu.biz/t/60/1420545595x1822611422.bmp