使用GSON的Java堆空间 [英] Java heap space with GSON

问题描述

我正在使用GSON创建一些大型JSON文件，以从GTFS（Google Transit）创建自定义JSON。问题是当我从对象类转换为JSON时：

I'm creating some big JSON file using GSON to create custom JSON from GTFS (Google Transit). The problem is when I'm converting from my object class to JSON:

  Gson gson = new Gson();
  String rutasJSON = gson.toJson(my_object);

它提供了这个例外：

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
    at java.util.Arrays.copyOf(Unknown Source)
    at java.lang.AbstractStringBuilder.expandCapacity(Unknown Source)
    at java.lang.AbstractStringBuilder.ensureCapacityInternal(Unknown Source)
    at java.lang.AbstractStringBuilder.append(Unknown Source)
    at java.lang.StringBuffer.append(Unknown Source)
    at java.io.StringWriter.write(Unknown Source)
    at com.google.gson.stream.JsonWriter.string(JsonWriter.java:544)
    at com.google.gson.stream.JsonWriter.writeDeferredName(JsonWriter.java:387)
    at com.google.gson.stream.JsonWriter.value(JsonWriter.java:402)
    at com.google.gson.internal.bind.TypeAdapters$13.write(TypeAdapters.java:353)
    at com.google.gson.internal.bind.TypeAdapters$13.write(TypeAdapters.java:337)
    at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:89)
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:195)
    at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
    at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)
    at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
    at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:89)
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:195)
    at com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:105)
    at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
    at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)
    at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
    at com.google.gson.Gson.toJson(Gson.java:586)
    at com.google.gson.Gson.toJson(Gson.java:565)
    at com.google.gson.Gson.toJson(Gson.java:520)
    at com.google.gson.Gson.toJson(Gson.java:500)
    at transporte.main(transporte.java:152)

我试图从此更改eclipse.ini：

I've tried to change eclipse.ini from this:

-startup
plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.100.v20110502
-product
org.eclipse.epp.package.jee.product
--launcher.defaultAction
openFile
--launcher.XXMaxPermSize
256M
-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
--launcher.defaultAction
openFile
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms40m
-Xmx512m

为此：

-startup
plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.100.v20110502
-product
org.eclipse.epp.package.jee.product
--launcher.defaultAction
openFile
--launcher.XXMaxPermSize
1024M
-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
--launcher.defaultAction
openFile
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms512m
-Xmx512m

任何想法？

推荐答案

而不是调整JVM，可能是一个好主意，使用流API而不是加载在写入之前，整个json进入内存。

Instead of tweaking the JVM it might be a good idea to use a streaming API instead of loading the whole json into memory before writing it.

看看 https://sites.google.com/site/gson/streaming

这篇关于使用GSON的Java堆空间的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！