Refactor/Streamify

iostreams/BasicFileOutput.java

@@ -7,8 +7,7 @@ import java.io.*;
 
 public class BasicFileOutput {
   static String file = "BasicFileOutput.dat";
-  public static void
-  main(String[] args) throws IOException {
+  public static void main(String[] args) {
     try(
       BufferedReader in = new BufferedReader(
         new StringReader(
@@ -17,10 +16,9 @@ public class BasicFileOutput {
       PrintWriter out = new PrintWriter(
         new BufferedWriter(new FileWriter(file)))
     ) {
-      int lineCount = 1;
-      String s;
-      while((s = in.readLine()) != null )
-        out.println(lineCount++ + ": " + s);
+      in.lines().forEach(out::println);
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
     // Show the stored file:
     System.out.println(BufferedInputFile.read(file));

iostreams/BufferedInputFile.java

@@ -4,23 +4,20 @@
 // Visit http://OnJava8.com for more book information.
 // {ValidateByHand}
 import java.io.*;
+import java.util.stream.*;
 
 public class BufferedInputFile {
-  public static String
-  read(String filename) throws IOException {
-    try(
-      BufferedReader in = new BufferedReader(
-        new FileReader(filename))
-    ) {
-      String s;
-      StringBuilder sb = new StringBuilder();
-      while((s = in.readLine())!= null)
-        sb.append(s + "\n");
-      return sb.toString();
+  public static String read(String filename) {
+    try(BufferedReader in = new BufferedReader(
+      new FileReader(filename))) {
+      return in.lines()
+        .collect(Collectors.joining("\n"));
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
   }
-  public static void
-  main(String[] args) throws IOException {
-    System.out.print(read("BufferedInputFile.java"));
+  public static void main(String[] args) {
+    System.out.print(
+      read("BufferedInputFile.java"));
   }
 }

iostreams/FileOutputShortcut.java

@@ -7,8 +7,7 @@ import java.io.*;
 
 public class FileOutputShortcut {
   static String file = "FileOutputShortcut.dat";
-  public static void
-  main(String[] args) throws IOException {
+  public static void main(String[] args) {
     try(
       BufferedReader in = new BufferedReader(
         new StringReader(BufferedInputFile.read(
@@ -16,12 +15,10 @@ public class FileOutputShortcut {
       // Here's the shortcut:
       PrintWriter out = new PrintWriter(file)
     ) {
-      int lineCount = 1;
-      String s;
-      while((s = in.readLine()) != null )
-        out.println(lineCount++ + ": " + s);
+      in.lines().forEach(out::println);
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
-    // Show the stored file:
     System.out.println(BufferedInputFile.read(file));
   }
 }

iostreams/FormattedMemoryInput.java

@@ -6,8 +6,7 @@
 import java.io.*;
 
 public class FormattedMemoryInput {
-  public static void
-  main(String[] args) throws IOException {
+  public static void main(String[] args) {
     try(
       DataInputStream in = new DataInputStream(
         new ByteArrayInputStream(
@@ -18,7 +17,9 @@ public class FormattedMemoryInput {
       while(true)
         System.out.write((char)in.readByte());
     } catch(EOFException e) {
-      System.out.println("End of stream");
+      System.out.println("\nEnd of stream");
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
   }
 }

iostreams/StoringAndRecoveringData.java

@@ -5,8 +5,7 @@
 import java.io.*;
 
 public class StoringAndRecoveringData {
-  public static void
-  main(String[] args) throws IOException {
+  public static void main(String[] args) {
     try(
       DataOutputStream out = new DataOutputStream(
         new BufferedOutputStream(
@@ -16,6 +15,8 @@ public class StoringAndRecoveringData {
       out.writeUTF("That was pi");
       out.writeDouble(1.41413);
       out.writeUTF("Square root of 2");
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
     try(
       DataInputStream in = new DataInputStream(
@@ -28,6 +29,8 @@ public class StoringAndRecoveringData {
       System.out.println(in.readUTF());
       System.out.println(in.readDouble());
       System.out.println(in.readUTF());
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
   }
 }

iostreams/TestEOF.java

@@ -7,8 +7,7 @@
 import java.io.*;
 
 public class TestEOF {
-  public static void
-  main(String[] args) throws IOException {
+  public static void main(String[] args) {
     try(
       DataInputStream in = new DataInputStream(
         new BufferedInputStream(
@@ -16,6 +15,8 @@ public class TestEOF {
     ) {
       while(in.available() != 0)
         System.out.write(in.readByte());
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
   }
 }

iostreams/UsingRandomAccessFile.java

@@ -6,7 +6,7 @@ import java.io.*;
 
 public class UsingRandomAccessFile {
   static String file = "rtest.dat";
-  static void display() throws IOException {
+  public static void display() {
     try(
       RandomAccessFile rf =
         new RandomAccessFile(file, "r")
@@ -15,10 +15,11 @@ public class UsingRandomAccessFile {
         System.out.println(
           "Value " + i + ": " + rf.readDouble());
       System.out.println(rf.readUTF());
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
   }
-  public static void
-  main(String[] args) throws IOException {
+  public static void main(String[] args) {
     try(
       RandomAccessFile rf =
         new RandomAccessFile(file, "rw")
@@ -28,6 +29,8 @@ public class UsingRandomAccessFile {
       rf.writeUTF("The end of the file");
       rf.close();
       display();
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
     try(
       RandomAccessFile rf =
@@ -37,6 +40,8 @@ public class UsingRandomAccessFile {
       rf.writeDouble(47.0001);
       rf.close();
       display();
+    } catch(IOException e) {
+      throw new RuntimeException(e);
     }
   }
 }