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diff --git a/java/com/google/gerrit/server/ioutil/ColumnFormatter.java b/java/com/google/gerrit/server/ioutil/ColumnFormatter.java
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+++ b/java/com/google/gerrit/server/ioutil/ColumnFormatter.java
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+// Copyright (C) 2012 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.ioutil;
+
+import java.io.PrintWriter;
+
+/**
+ * Simple output formatter for column-oriented data, writing its output to a {@link
+ * java.io.PrintWriter} object. Handles escaping of the column data so that the resulting output is
+ * unambiguous and reasonably safe and machine parsable.
+ */
+public class ColumnFormatter {
+  private char columnSeparator;
+  private boolean firstColumn;
+  private final PrintWriter out;
+
+  /**
+   * @param out The writer to which output should be sent.
+   * @param columnSeparator A character that should serve as the separator token between columns of
+   *     output. As only non-printable characters in the column text are ever escaped, the column
+   *     separator must be a non-printable character if the output needs to be unambiguously parsed.
+   */
+  public ColumnFormatter(PrintWriter out, char columnSeparator) {
+    this.out = out;
+    this.columnSeparator = columnSeparator;
+    this.firstColumn = true;
+  }
+
+  /**
+   * Adds a text string as a new column in the current line of output, taking care of escaping as
+   * necessary.
+   *
+   * @param content the string to add.
+   */
+  public void addColumn(String content) {
+    if (!firstColumn) {
+      out.print(columnSeparator);
+    }
+    out.print(StringUtil.escapeString(content));
+    firstColumn = false;
+  }
+
+  /**
+   * Finishes the output by flushing the current line and takes care of any other cleanup action.
+   */
+  public void finish() {
+    nextLine();
+    out.flush();
+  }
+
+  /**
+   * Flushes the current line of output and makes the formatter ready to start receiving new column
+   * data for a new line (or end-of-file). If the current line is empty nothing is done, i.e.
+   * consecutive calls to this method without intervening calls to {@link #addColumn} will be
+   * squashed.
+   */
+  public void nextLine() {
+    if (!firstColumn) {
+      out.print('\n');
+      firstColumn = true;
+    }
+  }
+}