Merge branch 'master' of github.com:subaochen/java-tutorial

Author: subaochen

guide/code/exception/src/cn/edu/sdut/softlab/exception/DivTest.java

@@ -7,30 +7,28 @@
  */
 public class DivTest {
 
-	/**
-	 * 程序执行入口.
-	 *
-	 * @param args 命令行参数
-	 */
-	public static void main(String[] args) {
-		try {
-			int a = Integer.parseInt(args[0]);
-			int b = Integer.parseInt(args[1]);
-			int c = a / b;
-			System.out.println("您输入的两个数相除的结果是： " + c);
-
-		} catch (ArrayIndexOutOfBoundsException e) {
-			System.out.println("数组越界，运行程序时输入的参数个数不对。应该输入2个参数，您输入的参数个数是：" + args.length);
-			e.printStackTrace();
-		} catch (NumberFormatException e) {
-			System.out.println("数字格式异常，程序只能接受整数形式的参数");
-			e.printStackTrace();
-		} catch (ArithmeticException e) {
-			System.out.println("数学异常，除数不能为0");
-			e.printStackTrace();
-		} catch (Exception e) {
-			System.out.println("天知道发生了什么，总之情况不对");
-			e.printStackTrace();
-		}
-	}
+    /**
+     * 程序执行入口.
+     *
+     * @param args 命令行参数
+     */
+    public static void main(String[] args) {
+        try {
+            int a = Integer.parseInt(args[0]);
+            int b = Integer.parseInt(args[1]);
+            System.out.println("a/b = " + a / b);
+        } catch (ArrayIndexOutOfBoundsException e) {
+            System.out.println("数组越界，运行程序时输入的参数个数不对。应该输入2个参数，您输入的参数个数是：" + args.length);
+            e.printStackTrace();
+        } catch (NumberFormatException e) {
+            System.out.println("数字格式异常，程序只能接受整数形式的参数");
+            e.printStackTrace();
+        } catch (ArithmeticException e) {
+            System.out.println("数学异常，除数不能为0");
+            e.printStackTrace();
+        } catch (Exception e) {
+            System.out.println("天知道发生了什么，总之情况不对");
+            e.printStackTrace();
+        }
+    }
 }

guide/code/exception/src/cn/edu/sdut/softlab/exception/DivTestCLike.java

@@ -0,0 +1,30 @@
+package cn.edu.sdut.softlab.exception;
+
+public class DivTestCLike {
+    public static void main(String[] args) {
+        if(args.length != 2){
+            System.out.println("请提供2个参数!");
+            return;
+        }
+
+        if(args[1].equalsIgnoreCase("0")){
+            System.out.println("除数不能为0!");
+            return;
+        }
+
+        // 判断args[0]和args[1]是整数形式的字符串
+        if(!isIntegerStr(args[0]) || !isIntegerStr(args[1])) {
+            System.out.println("两个参数的格式不合法,无法转换为整数");
+            return;
+        }
+
+        int a = Integer.parseInt(args[0]);
+        int b = Integer.parseInt(args[1]);
+        System.out.println("a/b = " +  a/b);
+    }
+
+    private static boolean isIntegerStr(String arg) {
+        // TBD
+        return true;
+    }
+}

guide/code/exception/src/cn/edu/sdut/softlab/exception/DivTestNoException.java

@@ -15,7 +15,6 @@ public class DivTestNoException {
 	public static void main(String[] args) {
 		int a = Integer.parseInt(args[0]);
 		int b = Integer.parseInt(args[1]);
-		int c = a / b;
-		System.out.println("您输入的两个数相除的结果是： " + c);
+		System.out.println("a/b = " +  a/b);
 	}
 }

guide/exception.lyx

@@ -1618,7 +1618,7 @@ reference "fig:抛出异常和捕获异常的关系"
 placement tbph
 wide false
 sideways false
-status open
+status collapsed
 
 \begin_layout Plain Layout
 \align center
@@ -1657,6 +1657,29 @@ name "fig:抛出异常和捕获异常的关系"
 \end_inset
 
 
+\end_layout
+
+\begin_layout Standard
+\begin_inset Flex Tip
+status open
+
+\begin_layout Plain Layout
+翻一下JDK的源代码，也许有助于深刻理解Java的异常处理机制。比如
+\begin_inset Note Note
+status open
+
+\begin_layout Plain Layout
+这里寻找一个合适易懂的Java源代码，在：http://hg.openjdk.java.net/jdk10/jdk10/jdk/file/777356696811
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+
 \end_layout
 
 \begin_layout Exercise