Merge branch 'dev/exception' into 'master'

dev(hansbug): add problem of java try with resources

See merge request !3

data/1.Java初阶/9.控制执行流程/4.通过异常处理错误/config.json

@@ -283,7 +283,8 @@
     "exception.json",
     "using.json",
     "runtime_exception.json",
-    "checked_exception.json"
+    "checked_exception.json",
+    "with_resources.json"
   ],
   "title": "通过异常处理错误",
   "keywords_must": [

data/1.Java初阶/9.控制执行流程/4.通过异常处理错误/with_resources.json

+{
+  "type": "code_options",
+  "author": "HansBug",
+  "source": "with_resources.md",
+  "notebook_enable": false,
+  "exercise_id": "33e4376c5f924a4f890e6aa10d1c1544"
+}
\ No newline at end of file

data/1.Java初阶/9.控制执行流程/4.通过异常处理错误/with_resources.md

+# 资源对象管理
+
+现有如下的程序，可以从文件`myfile.txt`中读取文本内容，将行号以标准的格式输出到标准输出流，对于可能存在的异常情况（如文件不存在、无权限等）需要进行妥善处理，且需要**保证当文件读取完毕后文件对象被关闭**，如下所示
+
+```java
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Scanner;
+
+public class TestMain {
+    public static void main(String[] args) throws IOException {
+        String filePath = "myfile.txt";
+        InputStream fileStream = null;
+        try {
+            fileStream = new FileInputStream(filePath);
+            Scanner scanner = new Scanner(fileStream);
+            int lineno = 0;
+            while (scanner.hasNextLine()) {
+                lineno += 1;
+                String line = scanner.nextLine();
+                System.out.printf("%3d >>> %s%n", lineno, line);
+            }
+            System.out.println("(EOF)");
+        } catch (IOException e) {
+            System.err.printf("Error occurred when reading '%s'.%n", filePath);
+            System.exit(-1);
+        } finally {
+            if (fileStream != null) {
+                fileStream.close();
+            }
+        }
+    }
+}
+
+```
+
+请改写上述代码，使用`try_with_resource`的方法简化程序，并依然**确保文件对象在任意情况下均被关闭**。
+
+因此，下列修改方式正确的是：
+
+## 答案
+
+```java
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Scanner;
+
+public class TestMain {
+    public static void main(String[] args) {
+        String filePath = "myfile.txt";
+        try (
+                InputStream fileStream = new FileInputStream(filePath);
+                Scanner scanner = new Scanner(fileStream)
+        ) {
+            int lineno = 0;
+            while (scanner.hasNextLine()) {
+                lineno += 1;
+                String line = scanner.nextLine();
+                System.out.printf("%3d >>> %s%n", lineno, line);
+            }
+            System.out.println("(EOF)");
+        } catch (IOException e) {
+            System.err.printf("Error occurred when reading '%s'.%n", filePath);
+            System.exit(-1);
+        }
+    }
+}
+```
+
+## 选项
+
+### A
+
+```java
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Scanner;
+
+public class TestMain {
+    public static void main(String[] args) {
+        String filePath = "myfile.txt";
+        try {
+            InputStream fileStream = new FileInputStream(filePath);
+            Scanner scanner = new Scanner(fileStream);
+        } {
+            int lineno = 0;
+            while (scanner.hasNextLine()) {
+                lineno += 1;
+                String line = scanner.nextLine();
+                System.out.printf("%3d >>> %s%n", lineno, line);
+            }
+            System.out.println("(EOF)");
+        } catch (IOException e) {
+            System.err.printf("Error occurred when reading '%s'.%n", filePath);
+            System.exit(-1);
+        }
+    }
+}
+```
+
+### B
+
+```java
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Scanner;
+
+public class TestMain {
+    public static void main(String[] args) {
+        String filePath = "myfile.txt";
+        try (fileStream, scanner = new FileInputStream(filePath), new Scanner(fileStream)) {
+            int lineno = 0;
+            while (scanner.hasNextLine()) {
+                lineno += 1;
+                String line = scanner.nextLine();
+                System.out.printf("%3d >>> %s%n", lineno, line);
+            }
+            System.out.println("(EOF)");
+        } catch (IOException e) {
+            System.err.printf("Error occurred when reading '%s'.%n", filePath);
+            System.exit(-1);
+        }
+    }
+}
+```
+
+### C
+
+```java
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Scanner;
+
+public class TestMain {
+    public static void main(String[] args) {
+        String filePath = "myfile.txt";
+        try (InputStream fileStream = new FileInputStream(filePath)) {
+            Scanner scanner = new Scanner(fileStream);
+            int lineno = 0;
+            while (scanner.hasNextLine()) {
+                lineno += 1;
+                String line = scanner.nextLine();
+                System.out.printf("%3d >>> %s%n", lineno, line);
+            }
+            System.out.println("(EOF)");
+        } catch (IOException e) {
+            System.err.printf("Error occurred when reading '%s'.%n", filePath);
+            System.exit(-1);
+        }
+    }
+}
+```
+
+### D
+
+```java
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Scanner;
+
+public class TestMain {
+    public static void main(String[] args) {
+        String filePath = "myfile.txt";
+        try (
+                InputStream fileStream = new FileInputStream(filePath);
+                Scanner scanner = new Scanner(fileStream);
+                int lineno = 0
+        ) {
+            while (scanner.hasNextLine()) {
+                lineno += 1;
+                String line = scanner.nextLine();
+                System.out.printf("%3d >>> %s%n", lineno, line);
+            }
+            System.out.println("(EOF)");
+        } catch (IOException e) {
+            System.err.printf("Error occurred when reading '%s'.%n", filePath);
+            System.exit(-1);
+        }
+    }
+}
+```
+