TomlWriter#write methods delegate to TomlWriter#write(Object, Writer) to

take advantage of streaming when possible.

src/main/java/com/moandjiezana/toml/BooleanConverter.java

@@ -31,7 +31,7 @@ class BooleanConverter implements ValueConverter, ValueWriter {
 
   @Override
   public void write(Object value, WriterContext context) {
-    context.output.append(value.toString());
+    context.write(value.toString());
   }
 
   @Override

src/main/java/com/moandjiezana/toml/DateConverter.java

@@ -99,12 +99,12 @@ class DateConverter implements ValueConverter, ValueWriter {
     }
     dateFormat.setTimeZone(context.getTomlWriter().getTimeZone());
 
-    context.output.append(dateFormat.format(value));
+    context.write(dateFormat.format(value));
 
     if (customDateFormat == null) {
       Calendar calendar = context.getTomlWriter().getCalendar();
       int tzOffset = (calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET)) / (60 * 1000);
-      context.output.append(String.format("%+03d:%02d", tzOffset / 60, tzOffset % 60));
+      context.write(String.format("%+03d:%02d", tzOffset / 60, tzOffset % 60));
     }
   }
 

src/main/java/com/moandjiezana/toml/MapValueWriter.java

@@ -37,14 +37,14 @@ class MapValueWriter implements ValueWriter {
       ValueWriter valueWriter = WRITERS.findWriterFor(fromValue);
       if (valueWriter.isPrimitiveType()) {
         context.indent();
-        context.output.append(quoteKey(key)).append(" = ");
+        context.write(quoteKey(key)).write(" = ");
         valueWriter.write(fromValue, context);
-        context.output.append('\n');
+        context.write('\n');
       } else if (valueWriter == PRIMITIVE_ARRAY_VALUE_WRITER) {
         context.setArrayKey(key.toString());
-        context.output.append(quoteKey(key)).append(" = ");
+        context.write(quoteKey(key)).write(" = ");
         valueWriter.write(fromValue, context);
-        context.output.append('\n');
+        context.write('\n');
       }
     }
 

src/main/java/com/moandjiezana/toml/NumberConverter.java

@@ -90,7 +90,7 @@ class NumberConverter implements ValueConverter, ValueWriter {
 
   @Override
   public void write(Object value, WriterContext context) {
-    context.output.append(value.toString());
+    context.write(value.toString());
   }
 
   @Override

src/main/java/com/moandjiezana/toml/PrimitiveArrayValueWriter.java

@@ -1,9 +1,9 @@
 package com.moandjiezana.toml;
 
-import java.util.Collection;
-
 import static com.moandjiezana.toml.ValueWriters.WRITERS;
 
+import java.util.Collection;
+
 class PrimitiveArrayValueWriter extends ArrayValueWriter {
   static final ValueWriter PRIMITIVE_ARRAY_VALUE_WRITER = new PrimitiveArrayValueWriter();
 
@@ -16,9 +16,9 @@ class PrimitiveArrayValueWriter extends ArrayValueWriter {
   public void write(Object value, WriterContext context) {
     Collection values = normalize(value);
 
-    context.output.append('[');
+    context.write('[');
     if (!context.getTomlWriter().wantTerseArrays()) {
-      context.output.append(' ');
+      context.write(' ');
     }
 
     boolean first = true;
@@ -37,16 +37,16 @@ class PrimitiveArrayValueWriter extends ArrayValueWriter {
                   " but found " + writer
           );
         }
-        context.output.append(", ");
+        context.write(", ");
       }
 
       WRITERS.write(elem, context);
     }
 
     if (!context.getTomlWriter().wantTerseArrays()) {
-      context.output.append(' ');
+      context.write(' ');
     }
-    context.output.append(']');
+    context.write(']');
   }
 
   private PrimitiveArrayValueWriter() {}

src/main/java/com/moandjiezana/toml/StringConverter.java

@@ -96,9 +96,9 @@ class StringConverter implements ValueConverter, ValueWriter {
 
   @Override
   public void write(Object value, WriterContext context) {
-    context.output.append('"');
-    escapeUnicode(value.toString(), context.output);
-    context.output.append('"');
+    context.write('"');
+    escapeUnicode(value.toString(), context);
+    context.write('"');
   }
 
   @Override
@@ -106,17 +106,17 @@ class StringConverter implements ValueConverter, ValueWriter {
     return true;
   }
 
-  private void escapeUnicode(String in, StringBuilder out) {
+  private void escapeUnicode(String in, WriterContext context) {
     for (int i = 0; i < in.length(); i++) {
       int codePoint = in.codePointAt(i);
       if (codePoint < specialCharacterEscapes.length && specialCharacterEscapes[codePoint] != null) {
-        out.append(specialCharacterEscapes[codePoint]);
+        context.write(specialCharacterEscapes[codePoint]);
       } else if (codePoint > 0x1f && codePoint < 0x7f) {
-        out.append(Character.toChars(codePoint));
+        context.write(Character.toChars(codePoint));
       } else if (codePoint <= 0xFFFF) {
-        out.append(String.format("\\u%04X", codePoint));
+        context.write(String.format("\\u%04X", codePoint));
       } else {
-        out.append(String.format("\\U%08X", codePoint));
+        context.write(String.format("\\U%08X", codePoint));
         // Skip the low surrogate, which will be the next in the code point sequence.
         i++;
       }

src/main/java/com/moandjiezana/toml/TomlWriter.java

@@ -1,14 +1,20 @@
 package com.moandjiezana.toml;
 
-import java.io.*;
+import static com.moandjiezana.toml.ValueWriters.WRITERS;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.StringWriter;
+import java.io.Writer;
 import java.text.DateFormat;
 import java.util.GregorianCalendar;
 import java.util.List;
 import java.util.Map;
 import java.util.TimeZone;
 
-import static com.moandjiezana.toml.ValueWriters.WRITERS;
-
 /**
  * <p>Converts Objects to TOML</p>
  *
@@ -45,29 +51,27 @@ public class TomlWriter {
    * @return a string containing the TOML representation of the given Object
    */
   public String write(Object from) {
-    return WRITERS.write(from, this);
-  }
-
-  /**
-   * Write an Object in TOML to a {@link Writer}.
-   *
-   * @param from the object to be written
-   * @param target the Writer to which TOML will be written
-   * @throws IOException if target.write() fails
-   */
-  public void write(Object from, Writer target) throws IOException {
-    target.write(write(from));
+    try {
+      StringWriter output = new StringWriter();
+      write(from, output);
+      
+      return output.toString();
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
   }
 
   /**
    * Write an Object in TOML to a {@link OutputStream}.
    *
    * @param from the object to be written
-   * @param target the OutputStream to which the TOML will be written
+   * @param target the OutputStream to which the TOML will be written. The stream is not closed after being written to.
    * @throws IOException if target.write() fails
    */
   public void write(Object from, OutputStream target) throws IOException {
-    target.write(write(from).getBytes());
+    OutputStreamWriter writer = new OutputStreamWriter(target);
+    write(from, writer);
+    writer.flush();
   }
 
   /**
@@ -79,10 +83,21 @@ public class TomlWriter {
    */
   public void write(Object from, File target) throws IOException {
     FileWriter writer = new FileWriter(target);
-    writer.write(write(from));
+    write(from, writer);
     writer.close();
   }
 
+  /**
+   * Write an Object in TOML to a {@link Writer}.
+   *
+   * @param from the object to be written
+   * @param target the Writer to which TOML will be written. The Writer is not closed.
+   * @throws IOException if target.write() fails
+   */
+  public void write(Object from, Writer target) throws IOException {
+    WRITERS.write(from, this, target);
+  }
+
   public WriterIndentationPolicy getIndentationPolicy() {
     return indentationPolicy;
   }

src/main/java/com/moandjiezana/toml/ValueWriters.java

@@ -9,6 +9,8 @@ import static com.moandjiezana.toml.PrimitiveArrayValueWriter.PRIMITIVE_ARRAY_VA
 import static com.moandjiezana.toml.StringConverter.STRING_PARSER;
 import static com.moandjiezana.toml.TableArrayValueWriter.TABLE_ARRAY_VALUE_WRITER;
 
+import java.io.Writer;
+
 class ValueWriters {
 
   static final ValueWriters WRITERS = new ValueWriters();
@@ -23,11 +25,9 @@ class ValueWriters {
     return OBJECT_VALUE_WRITER;
   }
 
-  String write(Object value, TomlWriter tomlWriter) {
-    WriterContext context = new WriterContext(tomlWriter);
+  void write(Object value, TomlWriter tomlWriter, Writer output) {
+    WriterContext context = new WriterContext(tomlWriter, output);
     write(value, context);
-
-    return context.output.toString();
   }
 
   void write(Object value, WriterContext context) {

src/main/java/com/moandjiezana/toml/WriterContext.java

@@ -1,5 +1,7 @@
 package com.moandjiezana.toml;
 
+import java.io.IOException;
+import java.io.Writer;
 import java.util.Arrays;
 
 class WriterContext {
@@ -8,19 +10,13 @@ class WriterContext {
   private String currentFieldIndent = "";
   private String arrayKey = null;
   private boolean isArrayOfTable = false;
+  private boolean empty = true;
   private final TomlWriter tomlWriter;
-  StringBuilder output = new StringBuilder();
+  private final Writer output;
 
-  WriterContext(String key, String tableIndent, StringBuilder output, TomlWriter tomlWriter) {
-    this.key = key;
-    this.currentTableIndent = tableIndent;
-    this.currentFieldIndent = tableIndent + fillStringWithSpaces(tomlWriter.getIndentationPolicy().getKeyValueIndent());
+  WriterContext(TomlWriter tomlWriter, Writer output) {
+    this.tomlWriter = tomlWriter;
     this.output = output;
-    this.tomlWriter = tomlWriter;
-  }
-
-  WriterContext(TomlWriter tomlWriter) {
-    this.tomlWriter = tomlWriter;
   }
 
   WriterContext pushTable(String newKey) {
@@ -31,37 +27,75 @@ class WriterContext {
 
     String fullKey = key + (key.isEmpty() ? newKey : "." + newKey);
 
-    return new WriterContext(fullKey, newIndent, output, tomlWriter);
+    WriterContext subContext = new WriterContext(fullKey, newIndent, output, tomlWriter);
+    if (!empty) {
+      subContext.empty = false;
+    }
+    
+    return subContext;
   }
 
   WriterContext pushTableFromArray() {
     WriterContext subContext = new WriterContext(key, currentTableIndent, output, tomlWriter);
+    if (!empty) {
+      subContext.empty = false;
+    }
     subContext.setIsArrayOfTable(true);
 
     return subContext;
   }
+  
+  WriterContext write(String s) {
+    try {
+      output.write(s);
+      if (s != null && !s.isEmpty()) {
+        empty = false;
+      }
+      
+      return this;
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  void write(char[] chars) {
+    for (char c : chars) {
+      write(c);
+    }
+  }
+  
+  WriterContext write(char c) {
+    try {
+      output.write(c);
+      empty = false;
+      
+      return this;
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
 
   void writeKey() {
     if (key.isEmpty()) {
       return;
     }
 
-    if (output.length() > 0) {
-      output.append('\n');
+    if (!empty) {
+      write('\n');
     }
 
-    output.append(currentTableIndent);
+    write(currentTableIndent);
 
     if (isArrayOfTable) {
-      output.append("[[").append(key).append("]]\n");
+      write("[[").write(key).write("]]\n");
     } else {
-      output.append('[').append(key).append("]\n");
+      write('[').write(key).write("]\n");
     }
   }
 
   void indent() {
     if (!key.isEmpty()) {
-      output.append(currentFieldIndent);
+      write(currentFieldIndent);
     }
   }
 
@@ -81,6 +115,14 @@ class WriterContext {
     return new String(chars);
   }
 
+  private WriterContext(String key, String tableIndent, Writer output, TomlWriter tomlWriter) {
+    this.key = key;
+    this.currentTableIndent = tableIndent;
+    this.currentFieldIndent = tableIndent + fillStringWithSpaces(tomlWriter.getIndentationPolicy().getKeyValueIndent());
+    this.output = output;
+    this.tomlWriter = tomlWriter;
+  }
+
   public TomlWriter getTomlWriter() {
     return tomlWriter;
   }