修改文本I/O内容

Author: kobe73er

andrew.txt

@@ -1,2 +1,2 @@
-John T Smith 90
-Eric K Jones 85
+Andrew 90
+Eric 80

scores.txt

@@ -0,0 +1,2 @@
+Programming 90
+Eric 80

scores1.txt

@@ -1,27 +1,20 @@
 package file;
 
+import java.io.File;
 import java.util.Scanner;
 
 public class ReadData {
-  public static void main(String[] args) throws Exception {
-    // Create a File instance
-    java.io.File file = new java.io.File("scores.txt");
 
-    // Create a Scanner for the file
+  public static void main(String[] args) throws Exception {
+    File file = new File("scores.txt");
     Scanner input = new Scanner(file);
-//    input.useDelimiter(".");
 
-    // Read data from a file
     while (input.hasNext()) {
-      String firstName = input.next();
-      String mi = input.next();
-      String lastName = input.next();
+      String name = input.next();
       int score = input.nextInt();
-      System.out.println(
-          firstName + " " + mi + " " + lastName + " " + score);
+      System.out.println("name:" + name + " score:" + score);
     }
 
-    // Close the file
     input.close();
   }
 }

src/main/java/file/ReadData.java

@@ -4,32 +4,28 @@
 import java.io.PrintWriter;
 import java.util.Scanner;
 
+//java ReplaceText sourceFile targetFile oldString newString
 public class ReplaceText {
 
   public static void main(String[] args) throws Exception {
-    // Check command line parameter usage
     if (args.length != 4) {
-      System.out.println(
-          "Usage: java ReplaceText sourceFile targetFile oldStr newStr");
+      System.out.println("Usage:java ReplaceText sourceFile targetFile oldStr newStr");
       System.exit(1);
     }
 
-    // Check if source file exists
     File sourceFile = new File(args[0]);
     if (!sourceFile.exists()) {
-      System.out.println("Source file " + args[0] + " does not exist");
+      System.out.println("Source file " + args[0] + " does not exist!");
       System.exit(2);
     }
 
-    // Check if target file exists
     File targetFile = new File(args[1]);
     if (targetFile.exists()) {
-      System.out.println("Target file " + args[1] + " already exists");
+      System.out.println("Target file " + args[1] + " already exists!");
       System.exit(3);
     }
 
     try (
-        // Create input and output files
         Scanner input = new Scanner(sourceFile);
         PrintWriter output = new PrintWriter(targetFile);
     ) {

src/main/java/file/ReplaceText.class

@@ -5,17 +5,16 @@
 public class TestFileClass {
 
   public static void main(String[] args) {
-    File file = new File("andrew.txt");
+    File file = new File("test/andrew.txt");
     System.out.println("Does it exists? " + file.exists());
-    System.out.println("The file has " + file.length() + " bytes");
-    System.out.println("Can it be read? " + file.canRead());
-
-    System.out.println("Can it be written? " + file.canWrite());
-    System.out.println("Is it a directory? " + file.isDirectory());
-    System.out.println("Is it a file? " + file.isFile());
-    System.out.println("Is it absolute? " + file.isAbsolute());
-    System.out.println("Is it hidden? " + file.isHidden());
-    System.out.println("Absolute path is " + file.getAbsolutePath());
-    System.out.println("Last modified on " + new java.util.Date(file.lastModified()));
+    System.out.println("The file has "+file.length()+" bytes");
+    System.out.println("Can it be read? "+file.canRead());
+    System.out.println("Can it be write? "+file.canWrite());
+    System.out.println("Is it a directory? "+file.isDirectory());
+    System.out.println("Is it a file? "+file.isFile());
+    System.out.println("Is it absolute? "+file.isAbsolute());
+    System.out.println("Is it hidden? "+file.isHidden());
+    System.out.println("Absolute path is ? "+file.getAbsolutePath());
+    System.out.println("Last modified on ? "+new java.util.Date(file.lastModified()));
   }
 }

src/main/java/file/ReplaceText.java

@@ -1,26 +1,27 @@
 package file;
 
+import java.io.File;
 import java.io.FileNotFoundException;
+import java.io.PrintWriter;
 
 public class WriteData {
 
-  public static void main(String[] args) throws Exception {
-    java.io.File file = new java.io.File("scores.txt");
-    if (file.exists()) {
-      System.out.println("File already exists");
+  public static void main(String[] args) throws FileNotFoundException {
+    File file = new File("scores.txt");
+    if(file.exists()){
+      System.out.println("File already exists!");
       System.exit(0);
     }
 
-    // Create a file
-    java.io.PrintWriter output = new java.io.PrintWriter(file);
+    PrintWriter output = new PrintWriter(file);
 
-    // Write formatted output to the file
-    output.print("John T Smith ");
+    output.print("Andrew Programming ");
     output.println(90);
-    output.print("Eric K Jones ");
-    output.println(85);
 
-    // Close the file
+    output.print("Eric ");
+    output.println(80);
+
     output.close();
   }
+
 }

src/main/java/file/TestFileClass.java

@@ -1,23 +1,28 @@
 package file;
 
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.PrintWriter;
+
 public class WriteDataWithAutoClose {
 
-  public static void main(String[] args) throws Exception {
-    java.io.File file = new java.io.File("scores.txt");
+  public static void main(String[] args) throws FileNotFoundException {
+    File file = new File("scores.txt");
     if (file.exists()) {
-      System.out.println("File already exists");
+      System.out.println("File already exists!");
       System.exit(0);
     }
 
-    try (
-        // Create a file
-        java.io.PrintWriter output = new java.io.PrintWriter(file);
-    ) {
-      // Write formatted output to the file
-      output.print("John T Smith ");
+
+    try(PrintWriter output = new PrintWriter(file)){
+      output.print("Andrew Programming1111111");
       output.println(90);
-      output.print("Eric K Jones ");
-      output.println(85);
+
+      output.print("Eric");
+      output.println(80);
     }
+
   }
+
 }
+

src/main/java/file/WriteData.java

@@ -0,0 +1 @@
+This is a test!