StackOverflowError for large maps

[GoogleCodeExporter]

What steps will reproduce the problem?

  public void testLargeGsonMapRoundTrip() throws Exception {
    Map<Long, Long> original = Maps.newHashMap();
    for (long i = 0; i < 50000; i++) {
      original.put(i, i + 1);
    }

    Gson gson = new Gson();
    String json = gson.toJson(original);

    Type longToLong = new TypeToken<Map<Long, Long>>(){}.getType();
    gson.fromJson(json, longToLong);
  }

What is the expected output? 

Gson should not recurse when parsing map entries. Parsing JSON is not that 
hard, so I suggest not using Javacc. 

What do you see instead?

com.google.gson.JsonParseException: Failed parsing JSON source: 
java.io.StringReader@186d484 to Json
    at com.google.gson.JsonParser.parse(JsonParser.java:61)
    at com.google.gson.Gson.fromJson(Gson.java:443)
    at com.google.gson.Gson.fromJson(Gson.java:396)
...

Caused by: java.lang.StackOverflowError
    at 
com.google.gson.JsonParserJavacc.jj_3R_5(JsonParserJavacc.java:449)
    at 
com.google.gson.JsonParserJavacc.jj_3R_4(JsonParserJavacc.java:456)
    at 
com.google.gson.JsonParserJavacc.jj_3R_2(JsonParserJavacc.java:443)
    at 
com.google.gson.JsonParserJavacc.jj_3_1(JsonParserJavacc.java:462)
    at 
com.google.gson.JsonParserJavacc.jj_2_1(JsonParserJavacc.java:428)
    at 
com.google.gson.JsonParserJavacc.JsonNumber(JsonParserJavacc.java:276)
    at 
com.google.gson.JsonParserJavacc.JsonValue(JsonParserJavacc.java:213)
    at com.google.gson.JsonParserJavacc.Pair(JsonParserJavacc.java:112)
    at 
com.google.gson.JsonParserJavacc.Members(JsonParserJavacc.java:95)
    at 
com.google.gson.JsonParserJavacc.Members(JsonParserJavacc.java:99)
...

What version of the product are you using? On what operating system?

1.4 (in google3)

Original issue reported on code.google.com by skybr...@google.com on 9 Mar 2010 at 7:44

[GoogleCodeExporter]

I have the same problem. My Input is a 18MB json file, which has basically the
structure of Map<String, <Map, <String, Map<String, String>>>>

(I 'm not at liberty to provide the file)

There are only few keys on first level, so each "value" is quite large

Original comment by CptMa...@googlemail.com on 4 May 2010 at 9:26

[GoogleCodeExporter]

r543 fixes this issue. Thanks for the bug report. The fix also improved Gson
performance by 20-30%.

Original comment by inder123 on 19 May 2010 at 9:25

• Changed state: Fixed