\u7cfb\u7edf\u8c03\u7528\u5916\u90e8\u63a5\u53e3\u83b7\u53d6\u6570\u636e\u540c\u6b65\u81f3\u672c\u5730\u5e93\uff0c\u65e0\u6cd5100%\u540c\u6b65\u6210\u529f\u3002<\/p>\n\n\n\n
\u67e5\u770b\u65e5\u5fd7\u540e\u6700\u7ec8\u5b9a\u4f4d\u5230\u662f\u7531\u4e8e fastjson \u5de5\u5177\u7c7b\u89e3\u6790 json \u6587\u4ef6\u65f6\u7531\u4e8e\u6587\u4ef6\u8fc7\u5927\u5230\u5bfc\u81f4OOM\u3002\u5355\u72ec\u8c03\u7528\u63a5\u53e3\u540e\u53d1\u73b0\u8fd4\u56de\u7684\u6570\u636e\u91cf\u8fbe\u5230\u4e86300M\u3002<\/p>\n\n\n\n
\u9519\u8bef\u4fe1\u606f\uff1a<\/p>\n\n\n\n
java.lang.OutOfMemoryError: Java heap space\n at com.alibaba.fastjson.serializer.SerializeWriter.expandCapacity(SerializeWriter.java:290)\n at com.alibaba.fastjson.serializer.SerializeWriter.writeFieldValueStringWithDoubleQuoteCheck(SerializeWriter.java:1487)\n at com.alibaba.fastjson.serializer.ASMSerializer_1_BigJsonPO.write(Unknown Source)\n at com.alibaba.fastjson.serializer.ListSerializer.write(ListSerializer.java:130)\n at com.alibaba.fastjson.serializer.JSONSerializer.write(JSONSerializer.java:278)\n at com.alibaba.fastjson.JSON.toJSONString(JSON.java:665)\n at com.alibaba.fastjson.JSON.toJSONString(JSON.java:607)\n at com.alibaba.fastjson.JSON.toJSONString(JSON.java:572)<\/code><\/pre>\n\n\n\n\u5c1d\u8bd5\u89e3\u51b3<\/h1>\n\n\n\n\u6362\u89e3\u6790\u5de5\u5177<\/h2>\n\n\n\n
\u5c06\u89e3\u6790\u5de5\u5177\u7531 fastjson \u6362\u4e3a hutool \u4e2d\u7684 json \u5de5\u5177\u7c7b\u540e\u91cd\u8bd5\uff1a\u5931\u8d25\uff01\uff01\uff01<\/p>\n\n\n\n
\u52a0\u5927\u5185\u5b58<\/h2>\n\n\n\n
\u9879\u76ee\u91c7\u7528\u7684\u65f6\u5fae\u670d\u52a1\u67b6\u6784\uff0c\u542f\u52a8\u65f6\u6307\u5b9a\u4e86JVM\u5806\u5185\u5b58\u521d\u59cb\u5927\u5c0f\u53ca\u6700\u5927\u503c\uff1aXms300m -Xmx2048m\uff0c\u4fee\u6539\u6700\u5927\u503c\u53c2\u6570\uff08\u4fee\u6539\u81f34096m\uff09\u540e\u91cd\u542f\u670d\u52a1\uff0c\u518d\u6b21\u5c1d\u8bd5\uff1a\u5931\u8d25\uff01\uff01\uff01<\/p>\n\n\n\n
\u6700\u7ec8\u65b9\u6848<\/h1>\n\n\n\n
\u67e5\u9605\u8d44\u6599\u540e\u53d1\u73b0\u662fFastjson\u4f7f\u7528\u65b9\u5f0f\u4e0d\u5bf9\uff0c\u4e0d\u80fd\u76f4\u63a5\u4f7f\u7528JSONArray.parseArray()\uff0c\u5f53\u9700\u8981\u5904\u7406\u8d85\u5927JSON\u6587\u672c\u65f6\uff0c\u9700\u8981\u4f7f\u7528Stream API\uff08\u7248\u672c>=1.1.32\uff09<\/p>\n\n\n\n
\u5f15\u5165\u4f9d\u8d56<\/h3>\n\n\n\n <dependency>\n <groupId>cn.hutool<\/groupId>\n <artifactId>hutool-all<\/artifactId>\n <version>5.7.4<\/version>\n <\/dependency> \n<!-- https:\/\/mvnrepository.com\/artifact\/com.alibaba\/fastjson -->\n <dependency>\n <groupId>com.alibaba<\/groupId>\n <artifactId>fastjson<\/artifactId>\n <version>1.2.36<\/version>\n <\/dependency><\/code><\/pre>\n\n\n\n\u65b0\u5efa\u4e00\u4e2apo\u7c7b<\/h3>\n\n\n\n
\u7528\u4e8e\u6d4b\u8bd5json\u5b57\u7b26\u4e32\u4e0e\u5b9e\u4f53\u7c7b\u4e4b\u95f4\u7684\u7c7b\u578b\u8f6c\u6362\u3002<\/p>\n\n\n\n
@Data\npublic class BigJsonPO implements Serializable {\n\n private static final long serialVersionUID = -63528737089874523564L;\n\n private String key1;\n private String key2;\n private String key3;\n ...\n private String key100;\n}<\/code><\/pre>\n\n\n\n\u6a21\u62df\u6570\u636e<\/h3>\n\n\n\n\/\/ \u6a21\u62df\u6587\u4ef6\u7684\u8def\u5f84 \nprivate final String filePath = \"F:\\\\test-json\\\\createByFastJson.json\";\n@Test\n public void testWrite() {\n TimeInterval timeInterval = new TimeInterval();\n int dataCount = 200000;\n File file = new File(filePath);\n \/\/ \u9700\u8981\u8d4b\u503c\u7684\u5b9e\u4f53\u7c7b\u5b57\u6bb5\n List<Field> fieldList = Arrays.stream(ReflectUtil.getFields(BigJsonPO.class)).filter(f -> !StrUtil.equalsIgnoreCase(\"serialVersionUID\", f.getName())).collect(Collectors.toList());\n try {\n JSONWriter jsonWriter = new JSONWriter(new FileWriter(file));\n \/\/ \u5199\u5165 {\n jsonWriter.startObject();\n jsonWriter.writeKey(\"data\");\n \/\/ \u5199\u5165 [\n jsonWriter.startArray();\n for (int i = 1; i <= dataCount; i++) {\n \/\/ \u5199\u5165 {\n jsonWriter.startObject();\n for (int i1 = 0; i1 < fieldList.size(); i1++) {\n String name = fieldList.get(i1).getName();\n jsonWriter.writeKey(name);\n jsonWriter.writeValue((i1 + 1) + \"-\" + IdUtil.fastSimpleUUID());\n }\n \/\/ \u5199\u5165 }\n jsonWriter.endObject();\n }\n \/\/ \u5199\u5165 ]\n jsonWriter.endArray();\n \/\/ \u5199\u5165 }\n jsonWriter.endObject();\n jsonWriter.close();\n System.out.println(\"\u6587\u4ef6\u5927\u5c0f\uff1a\u3010\" + FileUtil.size(file) \/ (1024 * 1024) + \"M\u3011\uff0c\u5199\u5165\u6570\u636e\uff1a\u3010\" + dataCount + \"\u3011\u6761\uff0c\u8017\u65f6\uff1a\u3010\" + timeInterval.intervalMs() + \"\u3011ms\");\n } catch (IOException e) {\n e.printStackTrace();\n }<\/code><\/pre>\n\n\n\n\u8bfb\u53d6\u6570\u636e<\/h3>\n\n\n\n @Test\n public void testParse() {\n TimeInterval timeInterval = new TimeInterval();\n try {\n File file = new File(filePath);\n List<BigJsonPO> list = this.parseBigJsonStr(new FileReader(file), \"data\", BigJsonPO.class);\n System.out.println(\"\u6587\u4ef6\u5927\u5c0f\uff1a\u3010\" + FileUtil.size(file) \/ (1024 * 1024) + \"M\u3011\uff0c\u89e3\u6790\u6570\u636e\uff1a\u3010\" + list.size() + \"\u3011\u6761\uff0c\u8017\u65f6\uff1a\u3010\" + timeInterval.intervalMs() + \"\u3011ms\");\n } catch (Exception e) {\n e.printStackTrace();\n }\n }\n\n\/**\n * \u89e3\u6790 \u5927 json \u5bf9\u8c61\uff0c\u683c\u5f0f\uff1a\n * {\n * jsonArrKey :[ \"key1\":\"value1\"...]\n * }\n * @param reader\n * @param jsonArrKey\n * @param jsonArrKeyType\n * @param <T>\n * @return\n *\/\n private <T> List<T> parseBigJsonStr(Reader reader, String jsonArrKey, Class<T> jsonArrKeyType) {\n List<T> list = new ArrayList<>();\n try {\n JSONReader jsonReader = new JSONReader(reader);\n jsonReader.startObject();\n while (jsonReader.hasNext()) {\n String tempJsonKey = jsonReader.readObject(String.class);\n if (StrUtil.equalsIgnoreCase(jsonArrKey, tempJsonKey)) {\n jsonReader.startArray();\n while (jsonReader.hasNext()) {\n list.add(jsonReader.readObject(jsonArrKeyType));\n }\n jsonReader.endArray();\n }\n }\n jsonReader.endObject();\n jsonReader.close();\n } catch (Exception e) {\n e.printStackTrace();\n }\n return list;\n }<\/code><\/pre>\n\n\n\n\u81f3\u6b64\uff0c\u95ee\u9898\u5b8c\u7f8e\u89e3\u51b3\u3002<\/p>\n\n\n\n
\u5176\u4ed6\u89e3\u51b3\u65b9\u6848<\/h1>\n\n\n\n
\u641c\u4e86\u8d44\u6599\u540e\u53d1\u73b0\uff0c jackson \u7c7b\u5e93\u4e5f\u53ef\u4ee5\u89e3\u51b3\u95ee\u9898\uff0c\u4ee3\u7801\u7c7b\u4f3c\u3002<\/p>\n\n\n\n
\u5f15\u5165\u4f9d\u8d56<\/h3>\n\n\n\n <dependency>\n <groupId>cn.hutool<\/groupId>\n <artifactId>hutool-all<\/artifactId>\n <version>5.7.4<\/version>\n <\/dependency> \n\n<!-- https:\/\/mvnrepository.com\/artifact\/com.fasterxml.jackson.core\/jackson-core -->\n <dependency>\n <groupId>com.fasterxml.jackson.core<\/groupId>\n <artifactId>jackson-core<\/artifactId>\n <version>2.13.1<\/version>\n <\/dependency>\n\n <!-- https:\/\/mvnrepository.com\/artifact\/com.fasterxml.jackson.core\/jackson-databind -->\n <dependency>\n <groupId>com.fasterxml.jackson.core<\/groupId>\n <artifactId>jackson-databind<\/artifactId>\n <version>2.13.1<\/version>\n <\/dependency><\/code><\/pre>\n\n\n\n\u6a21\u62df\u6570\u636e<\/h3>\n\n\n\n @Test\n public void testWriteJson() {\n TimeInterval timeInterval = new TimeInterval();\n int dataCount = 100000;\n this.writeJson(filePath, dataCount, BigJsonPO.class);\n System.out.println(\"\u5199\u5165\u6570\u636e\u91cf\uff1a\" + dataCount + \"\uff0c\u8017\u65f6\uff1a\" + timeInterval.intervalMs());\n }\n\n private <T> void writeJson(String filePath, long dataCount, Class<T> poClass) {\n JsonFactory factory = JsonFactory.builder().build();\n try {\n List<Field> fieldList = Arrays.stream(ReflectUtil.getFields(poClass)).filter(f -> !StrUtil.equalsIgnoreCase(\"serialVersionUID\", f.getName())).collect(Collectors.toList());\n JsonGenerator jg = factory.createGenerator(new File(filePath), JsonEncoding.UTF8);\n jg.writeStartObject();\n jg.writeFieldName(\"data\");\n jg.writeStartArray();\n for (long i = 0; i < dataCount; i++) {\n jg.writeStartObject();\n for (int j = 0; j < fieldList.size(); j++) {\n String fieldName = fieldList.get(j).getName();\n Object value = (j + 1) + \"-\" + IdUtil.fastSimpleUUID();\n jg.writeObjectField(fieldName, value);\n }\n jg.writeEndObject();\n }\n jg.writeEndArray();\n jg.writeEndObject();\n jg.close();\n } catch (IOException e) {\n e.printStackTrace();\n }\n }<\/code><\/pre>\n\n\n\n\u8bfb\u53d6\u6570\u636e<\/h3>\n\n\n\n@Test\n public void testParseJson() {\n TimeInterval timeInterval = new TimeInterval();\n JsonFactory factory = JsonFactory.builder()\n .build().setCodec(new ObjectMapper());\n List<BigJsonPO> list = new ArrayList<>();\n File file = new File(filePath);\n try {\n JsonParser jp = factory.createParser(file);\n JsonToken outToken = jp.nextToken();\n \/\/ \u6821\u9a8c\u683c\u5f0f\u662f\u5426\u6b63\u786e\n if (outToken != JsonToken.START_OBJECT) {\n throw new RuntimeException(\"Error json string\");\n }\n \/\/ \u83b7\u53d6\u5f53\u524d\u8282\u70b9\u540d\u79f0\n String currentName;\n \/\/ \u5faa\u73af \u76f4\u81f3 \u7ed3\u5c3e \u7b26\u53f7 \u51fa\u73b0\n while (jp.nextToken() != JsonToken.END_OBJECT) {\n currentName = jp.getCurrentName();\n if (jp.nextToken() == JsonToken.START_ARRAY) {\n if (currentName.equals(\"data\")) {\n while (jp.nextToken() != JsonToken.END_ARRAY) {\n BigJsonPO po = jp.readValueAs(BigJsonPO.class);\n list.add(po);\n }\n } else {\n jp.skipChildren();\n }\n } else {\n jp.skipChildren();\n }\n }\n jp.close();\n } catch (IOException e) {\n e.printStackTrace();\n }\n System.out.println(\"\u6587\u4ef6\u5927\u5c0f\uff1a\u3010\" + FileUtil.size(file) \/ (1024 * 1024) + \"M\u3011\uff0c\u89e3\u6790\u6570\u636e\uff1a\u3010\" + list.size() + \"\u3011\u6761\uff0c\u8017\u65f6\uff1a\u3010\" + timeInterval.intervalMs() + \"\u3011ms\");\n }<\/code><\/pre>\n\n\n\n\u6027\u80fd\u5bf9\u6bd4<\/h1>\n\n\n\n
\u672c\u673a\u5904\u7406\u5668\uff1a ADM 4700U 8\u6838 16G<\/p>\n\n\n\n
fastjson VS jackson<\/strong><\/p>\n\n\n\n\u6570\u636e\u91cf\uff08W\uff09<\/th> \u6570\u636e\u5927\u5c0f(M)<\/th> \u5199\u5165\u8017\u65f6\uff08ms\uff09<\/th> \u89e3\u6790\u8017\u65f6\uff08ms\uff09<\/th><\/tr><\/thead> 0.2<\/td> 8.74<\/td> 316\/198<\/td> 298\/338<\/td><\/tr> 2<\/td> 87.4<\/td> 1397\/1007<\/td> 937\/848<\/td><\/tr> 20<\/td> 874<\/td> 12103\/8224<\/td> 9479\/9992<\/td><\/tr> 200<\/td> 8430<\/td> 105898\/79756<\/td> \u6682\u672a\u6d4b\u8bd5<\/td><\/tr><\/tbody><\/table><\/figure>\n","protected":false},"excerpt":{"rendered":"\u80cc\u666f \u7cfb\u7edf\u8c03\u7528\u5916\u90e8\u63a5\u53e3\u83b7\u53d6\u6570\u636e\u540c\u6b65\u81f3\u672c\u5730\u5e93\uff0c\u65e0\u6cd5100%\u540c\u6b65\u6210\u529f\u3002 \u95ee\u9898\u5b9a\u4f4d \u67e5\u770b\u65e5\u5fd7\u540e\u6700\u7ec8\u5b9a\u4f4d\u5230\u662f\u7531\u4e8e fa […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[20],"class_list":["post-92","post","type-post","status-publish","format-standard","hentry","category-java","tag-json"],"_links":{"self":[{"href":"https:\/\/zhoujibin.com\/index.php?rest_route=\/wp\/v2\/posts\/92"}],"collection":[{"href":"https:\/\/zhoujibin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zhoujibin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zhoujibin.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zhoujibin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=92"}],"version-history":[{"count":10,"href":"https:\/\/zhoujibin.com\/index.php?rest_route=\/wp\/v2\/posts\/92\/revisions"}],"predecessor-version":[{"id":222,"href":"https:\/\/zhoujibin.com\/index.php?rest_route=\/wp\/v2\/posts\/92\/revisions\/222"}],"wp:attachment":[{"href":"https:\/\/zhoujibin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=92"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zhoujibin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=92"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zhoujibin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=92"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}