动手动脑
public class CatchWho {
public static void main(String[] args) {
try {
try {
throw new ArrayIndexOutOfBoundsException();
}
catch(ArrayIndexOutOfBoundsException e) {
System.out.println( "ArrayIndexOutOfBoundsException" + "/内层try-catch");
}
throw new ArithmeticException();
}
catch(ArithmeticException e) {
System.out.println("发生ArithmeticException");
}
catch(ArrayIndexOutOfBoundsException e) {
System.out.println( "ArrayIndexOutOfBoundsException" + "/外层try-catch");
}
}
}
image
public class CatchWho2 {
public static void main(String[] args) {
try {
try {
throw new ArrayIndexOutOfBoundsException();
} catch (ArithmeticException e) {
System.out.println("ArrayIndexOutOfBoundsException" + "try-catch");
}
throw new ArithmeticException();
} catch (ArithmeticException e) {
System.out.println("·¢ÉúArithmeticException");
} catch (ArrayIndexOutOfBoundsException e) {
System.out.println("ArrayIndexOutOfBoundsException" + "2132123aaatry-catch");
}
}
}
上面是同样道理
观测异常处理，catch抓取几个异常
import java.io.*;
public class CheckedExceptionDemo {
public static void main(String[] args) {
try {
BufferedReader buf = new BufferedReader(
new InputStreamReader(System.in)); // 抛出受控的异常
System.out.print("请输入整数: ");
int input = Integer.parseInt(buf.readLine()); // 有可能引发运行时异常
System.out.println("input x 10 = " + (input * 10));
}
// 以下异常处理语句块是必须的，否则无法通过编译
catch (IOException e) {
System.out.println("I/O错误");
}
// 以下异常处理语句块可以省略，不影响编译，但在运行时出错
catch (NumberFormatException e) {
System.out.println("输入必须为整数");
}
}
}
image
image
查看try-catch先后嵌套顺序
public class EmbededFinally {
public static void main(String args[]) {
int result;
try {
System.out.println("in Level 1");
try {
System.out.println("in Level 2");
// result=100/0; //Level 2
try {
System.out.println("in Level 3");
result = 100 / 0; // Level 3
}
catch (Exception e) {
System.out.println("Level 3:" + e.getClass().toString());
}
finally {
System.out.println("In Level 3 finally");
}
// result=100/0; //Level 2
}
catch (Exception e) {
System.out.println("Level 2:" + e.getClass().toString());
} finally {
System.out.println("In Level 2 finally");
}
// result = 100 / 0; //level 1
}
catch (Exception e) {
System.out.println("Level 1:" + e.getClass().toString());
}
finally {
System.out.println("In Level 1 finally");
}
}
}
image
浮点数除以0是infinity，不是异常
public class ThrowDemo {
public static void main(String[] args) {
// try {
double data = 100 / 0.0;
System.out.println("浮点数除以零：" + data);
// if(String.valueOf(data).equals("Infinity"))
// {
// System.out.println("In Here" );
// throw new ArithmeticException("除零异常");
// }
// }
// catch(ArithmeticException e) {
// System.out.println(e);
// }
}
```
import java.io.*;
public class ThrowMultiExceptionsDemo {
public static void main(String[] args) {
try {
throwsTest();
} catch (IOException e) {
System.out.println("捕捉异常");
}
}
private static void throwsTest() throws ArithmeticException, IOException {
System.out.println("这只是一个测试");
// 程序处理过程假设发生异常
throw new IOException();
// throw new ArithmeticException();
}
}
