The best Parser.java you ever seen

Parser.java

@@ -1,46 +1,48 @@
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-/**
- * This class is thread safe.
- */
+import java.io.*;
+import java.util.stream.IntStream;
+
 public class Parser {
-  private File file;
-  public synchronized void setFile(File f) {
-    file = f;
+
+  public final File file;
+  private final FileInputStream inputStream;
+
+  public Parser(File file) throws IOException {
+    if (file == null) throw new IOException("input file is null");
+    this.file = file;
+    this.inputStream = new FileInputStream(file);
   }
-  public synchronized File getFile() {
-    return file;
+
+  public void saveContent(String content) throws IOException {
+    var outputStream = new FileOutputStream(this.file);
+    for (int i : IntStream.range(0, content.length()).toArray()) {
+      outputStream.write(content.charAt(i));
+    }
+    outputStream.close();
   }
+
   public String getContent() throws IOException {
-    FileInputStream i = new FileInputStream(file);
-    String output = "";
-    int data;
-    while ((data = i.read()) > 0) {
-      output += (char) data;
-    }
-    return output;
+    return this.iterateOverContent(false);
   }
+
   public String getContentWithoutUnicode() throws IOException {
-    FileInputStream i = new FileInputStream(file);
-    String output = "";
-    int data;
-    while ((data = i.read()) > 0) {
-      if (data < 0x80) {
-        output += (char) data;
-      }
+    return this.iterateOverContent(true);
+  }
+
+  private String iterateOverContent(boolean unicode) throws IOException {
+    var builder = new StringBuilder();
+    int content;
+    while ((content = this.inputStream.read()) > 0) {
+      this.contentAsChar(unicode, builder, content);
     }
-    return output;
+    this.inputStream.close();
+    return builder.toString();
   }
-  public void saveContent(String content) {
-    FileOutputStream o = new FileOutputStream(file);
-    try {
-      for (int i = 0; i < content.length(); i += 1) {
-        o.write(content.charAt(i));
-      }
-    } catch (IOException e) {
-      e.printStackTrace();
+
+  private void contentAsChar(boolean unicode, StringBuilder builder, int content) {
+    if (unicode && content > 0x80) {
+      return;
     }
+    builder.append((char) content);
   }
+
 }