import java.util.Scanner;

public class homeWork01 {

public static String triangle(String s1,String s2,String s3){

String str="abcdefghijklmnopqrstuvwxyz!@#$%^&*()_+-=";

if(str.indexOf(s1)!=-1||str.indexOf(s2)!=-1||str.indexOf(s3)!=-1){

return "输入的是非法字符";

}

//判断输入的值是否是整数

if(isNumeric(s1)&&isNumeric(s2)&&isNumeric(s3)){

 

}else{

return"输入的数字不是整数";

}

int a = 0,b=0,c=0;

a=Integer.parseInt(s1);

b=Integer.parseInt(s2);

c=Integer.parseInt(s3);

if(a>=1&&a<=100&&b>=1&&b<=100&&c>=1&&c<=100){

if((a<b+c)&&(b<a+c)&&(c<a+b)){

if(a==b&&b==c){

return "等边三角形";

}

if(a==b||a==c||b==c){

return "等腰三角形";

}

if(a*a==b*b+c*c||b*b==a*a+c*c||c*c==a*a+b*b){

return"直角三角形";

}

return "一般三角形";

}else{

return"不构成三角形";

}

}else{

return "边的值不在范围内";

}

 

}

public static boolean isNumeric(String str1){  

  for (int i = str1.length();--i>=0;){    

   if (!Character.isDigit(str1.charAt(i))){  

    return false;  

   }  

  }  

  return true;  

}

public static double triangleArea(String s1,String s2,String s3){

int a = 0,b=0,c=0;

a=Integer.parseInt(s1);

b=Integer.parseInt(s2);

c=Integer.parseInt(s3);

float p=(float)(a+b+c)/2;

double area= Math.sqrt(p*(p-a)*(p-b)*(p-c));

return area;

 

}

public static int primeter(String s1,String s2,String s3){

int a = 0,b=0,c=0;

a=Integer.parseInt(s1);

b=Integer.parseInt(s2);

c=Integer.parseInt(s3);

return a+b+c;

}

public static void main(String []args){

System.out.println("请输入三角形的三条边：");

String s1=null;

String s2=null;

String s3=null;

Scanner scan=new Scanner(System.in);

s1=scan.next();

//如果输入的边长为0，则退出程序

 

s2=scan.next();

s3=scan.next();

 

System.out.println(triangle(s1,s2,s3));

System.out.println("三角形的面积为："+triangleArea(s1,s2,s3));

    System.out.println("三角形的边长为："+primeter(s1,s2,s3));

 

}

 

 

}

3、生成图形界面源代码

package mypack;

import java.awt.Font;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

 

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JTextField;

 

 

 

class ActionHandle{

public static String triangle(String s1,String s2,String s3){

String str="abcdefghijklmnopqrstuvwxyz!@#$%^&*()_+-=";

if(str.indexOf(s1)!=-1||str.indexOf(s2)!=-1||str.indexOf(s3)!=-1){

return "输入的是非法字符";

}

//判断输入的值是否是整数

if(isNumeric(s1)&&isNumeric(s2)&&isNumeric(s3)){

 

}else{

return"输入的数字不是整数";

}

int a = 0,b=0,c=0;

a=Integer.parseInt(s1);

b=Integer.parseInt(s2);

c=Integer.parseInt(s3);

if(a>=1&&a<=100&&b>=1&&b<=100&&c>=1&&c<=100){

if((a<b+c)&&(b<a+c)&&(c<a+b)){

if(a==b&&b==c){

return "等边三角形";

}

if(a==b||a==c||b==c){

return "等腰三角形";

}

if(a*a==b*b+c*c||b*b==a*a+c*c||c*c==a*a+b*b){

return"直角三角形";

}

return "一般三角形";

}else{

return"不构成三角形";

}

}else{

return "边的值不在范围内";

}

 

}

public static boolean isNumeric(String str1){  

  for (int i = str1.length();--i>=0;){    

   if (!Character.isDigit(str1.charAt(i))){  

    return false;  

   }  

  }  

  return true;  

}

public static double triangleArea(String s1,String s2,String s3){

int a = 0,b=0,c=0;

a=Integer.parseInt(s1);

b=Integer.parseInt(s2);

c=Integer.parseInt(s3);

float p=(float)(a+b+c)/2;

double area= Math.sqrt(p*(p-a)*(p-b)*(p-c));

return area;

 

}

public static int primeter(String s1,String s2,String s3){

int a = 0,b=0,c=0;

a=Integer.parseInt(s1);

b=Integer.parseInt(s2);

c=Integer.parseInt(s3);

return a+b+c;

}

private JFrame frame=new JFrame("三角形计算程序");

private JButton ok=new JButton("ok");

private JButton reset=new JButton("reset");

private JLabel infoLab=new JLabel("请输入三角形的三条边:");

private JLabel aLab=new JLabel("a:");

private JLabel bLab=new JLabel("b:");

private JLabel cLab=new JLabel("c:");

private JLabel styleLab=new JLabel("这个三角形是：");

private JLabel areaLab=new JLabel("面积是：");

private JLabel preLab=new JLabel("周长是：");

private JTextField aText=new JTextField();

private JTextField bText=new JTextField();

private JTextField cText=new JTextField();

public ActionHandle(){

Font fnt=new Font("Serief",Font.BOLD,12);

infoLab.setFont(fnt);

ok.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent arg0) {

// TODO Auto-generated method stub

if(arg0.getSource()==ok){

String a=aText.getText();

String b=bText.getText();

String c=cText.getText();

String style=triangle(a,b,c);

String area=String.valueOf(triangleArea(a,b,c));

String   pre=String.valueOf(primeter(a,b,c));

styleLab.setText("类型为："+style);

areaLab.setText("面积为："+area);

preLab.setText("周长为："+pre);

}

if(arg0.getSource()==reset){

aText.setText(" ");

bText.setText(" ");

cText.setText(" ");

}

}

 

});

frame.addWindowListener(new WindowAdapter(){

public void windowClosing(WindowEvent arg0){

System.exit(1);

}

});

frame.setLayout(null);

infoLab.setBounds(5, 5, 60, 20);

aLab.setBounds(5, 25, 60, 20);

aText.setBounds(65, 25, 60, 20);

bLab.setBounds(5,45, 60, 20);

bText.setBounds(65, 45, 60, 20);

cLab.setBounds(5,65, 60, 20);

cText.setBounds(65, 65, 60, 20);

ok.setBounds(5, 85, 60, 20);

reset.setBounds(65,85, 100, 20);

styleLab.setBounds(5, 105, 150, 20);

areaLab.setBounds(5, 125, 100, 20);

preLab.setBounds(5, 145, 100, 20);

frame.add(infoLab);

frame.add(aLab);

frame.add(aText);

frame.add(bLab);

frame.add(bText);

frame.add(cLab);

frame.add(cText);

frame.add(ok);

frame.add(reset);

frame.add(styleLab);

frame.add(areaLab);

frame.add(preLab);

frame.setSize(200,300);

frame.setLocation(500,200);

frame.setVisible(true);

}

}

 

public class homeWork04 {

public static void main(String []args){

new ActionHandle();

}

 

}