Add json output to Junit tests.

testing/android/junit/java/src/org/chromium/testing/local/JsonLogger.java

Index: testing/android/junit/java/src/org/chromium/testing/local/JsonLogger.java
diff --git a/testing/android/junit/java/src/org/chromium/testing/local/JsonLogger.java b/testing/android/junit/java/src/org/chromium/testing/local/JsonLogger.java
new file mode 100644
index 0000000000000000000000000000000000000000..a876e2cf55c22200924102f05b423343ce6ca4c2
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+++ b/testing/android/junit/java/src/org/chromium/testing/local/JsonLogger.java
@@ -0,0 +1,117 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.testing.local;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import org.junit.runner.Description;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.PrintStream;
+
+/*
+    Format of the json file mirrors the one generated by
+    build/android/pylib/results/json_results.py.
+    Below is an example json output.
+    {
+        "global_tags": [],
+        "all_tests": [
+            "test1",
+            "test2",
+        ],
+        "disabled_tests": [],
+        "per_iteration_data": [
+            {
+                "test1": [
+                    {
+                        "status": "SUCCESS",
+                        "elapsed_time_ms": 1,
+                        "output_snippet": "",
+                        "output_snippet_base64": "",
+                        "losless_snippet": "".
+                    }
+                ],
+                "test2": [
+                    {
+                        "status": "SUCCESS",
+                        "elapsed_time_ms": 1,
+                        "output_snippet": "",
+                        "output_snippet_base64": "",
+                        "losless_snippet": "".
+                    }
+                ]
+            }
+        ]
+    }
+*/
+
+/**
+ *  Creates json file with junit test information.
+ */
+public class JsonLogger {
+
+    private JSONObject mBaseJsonObject;
+    private JSONObject mBaseTestInfoJsonObject;
+    private File mOutputFile;
+
+    public JsonLogger(File outputFile) {
+        mBaseJsonObject = new JSONObject();
+        mBaseTestInfoJsonObject = new JSONObject();
+        mOutputFile = outputFile;
+
+        try {
+            mBaseJsonObject.put("global_tags", new JSONArray());
+            mBaseJsonObject.put("all_tests", new JSONArray());
+            mBaseJsonObject.put("disabled_tests", new JSONArray());
+            mBaseJsonObject.put("per_iteration_data",
+                                new JSONArray().put(mBaseTestInfoJsonObject));
+        } catch (JSONException e) {
+            System.err.println("Unable to create json output.");
+        }
+    }
+
+    /**
+     *  Add the results of a test run to the json output.
+     */
+    public void addTestResultInfo(Description test, boolean passed, long elapsedTimeMillis) {
+        JSONObject testInfoJsonObject = new JSONObject();
+
+        try {
+            testInfoJsonObject.put("status", (passed ? "SUCCESS" : "FAILURE"));
+            testInfoJsonObject.put("elapsed_time_ms", elapsedTimeMillis);
+            testInfoJsonObject.put("output_snippet", "");
+            testInfoJsonObject.put("output_snippet_base64", "");
+            testInfoJsonObject.put("losless_snippet", "");
+
+            if (mBaseTestInfoJsonObject.optJSONArray(testName(test)) == null) {
+                mBaseTestInfoJsonObject.put(testName(test), new JSONArray());
+                mBaseJsonObject.getJSONArray("all_tests").put(testName(test));
+            }
+            mBaseTestInfoJsonObject.getJSONArray(testName(test)).put(testInfoJsonObject);
+        } catch (JSONException e) {
+            System.err.println("Unable to log test to json output: " + testName(test));
+        }
+    }
+
+    /**
+     *  Writes the json output to a file.
+     */
+    public void writeJsonToFile() {
+        try {
+            PrintStream stream = new PrintStream(new FileOutputStream(mOutputFile));
+            stream.print(mBaseJsonObject);
+        } catch (FileNotFoundException e) {
+            System.err.println("File not found: " + mOutputFile.getPath());
+        }
+    }
+
+    private String testName(Description test) {
+        return test.getClassName() + "." + test.getMethodName();
+    }
+}