Jackson高性能的JSON处理 v2.16.1.zip

# Overview This project contains core low-level incremental ("streaming") parser and generator abstractions used by [Jackson Data Processor](https://github.com/FasterXML/jackson). It also includes the default implementation of handler types (parser, generator) that handle JSON format. The core abstractions are not JSON specific, although naming does contain 'JSON' in many places, due to historical reasons. Only packages that specifically contain word 'json' are JSON-specific. This package is the base on which [Jackson data-binding](https://github.com/FasterXML/jackson-databind) package builds on. It is licensed under [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0). Alternate data format implementations (like [Smile (binary JSON)](https://github.com/FasterXML/jackson-dataformats-binary/tree/master/smile), [XML](https://github.com/FasterXML/jackson-dataformat-xml), [CSV](https://github.com/FasterXML/jackson-dataformats-text/tree/master/csv), [Protobuf](https://github.com/FasterXML/jackson-dataformats-binary/tree/master/protobuf), and [CBOR](https://github.com/FasterXML/jackson-dataformats-binary/tree/master/cbor)) also build on this base package, implementing the core interfaces, making it possible to use standard [data-binding package](https://github.com/FasterXML/jackson-databind) regardless of underlying data format. Project contains versions 2.0 and above: source code for earlier (1.x) versions can be found from [Jackson-1](../../../jackson-1) github repo. ## Status | Type | Status | | ---- | ------ | | Build (CI) | [](https://github.com/FasterXML/jackson-core/actions/workflows/main.yml) | | Artifact | [](https://maven-badges.herokuapp.com/maven-central/com.fasterxml.jackson.core/jackson-core) | | OSS Sponsorship | [](https://tidelift.com/subscription/pkg/maven-com-fasterxml-jackson-core-jackson-core?utm_source=maven-com-fasterxml-jackson-core-jackson-core&utm_medium=referral&utm_campaign=readme) | | Javadocs | [](https://javadoc.io/doc/com.fasterxml.jackson.core/jackson-core) | | Code coverage (2.15) | [](https://codecov.io/github/FasterXML/jackson-core?branch=2.15) | | CodeQ (ClusterFuzz) | [](https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:jackson-core) | | OpenSSF Score | [](https://securityscorecards.dev/viewer/?uri=github.com/FasterXML/jackson-core) | # Get it! ## Maven Functionality of this package is contained in Java package `com.fasterxml.jackson.core`. To use the package, you need to use following Maven dependency: ```xml <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>${jackson.version.core}</version> </dependency> ``` or download jars from Maven repository or links on [Wiki](../../wiki). Core jar is a functional OSGi bundle, with proper import/export declarations. Package has no external dependencies, except for testing (which uses `JUnit`). ## Non-Maven For non-Maven use cases, you download jars from [Central Maven repository](https://repo1.maven.org/maven2/com/fasterxml/jackson/core/jackson-core/). Core jar is also a functional OSGi bundle, with proper import/export declarations, so it can be use on OSGi container as is. Jackson 2.10 and above include `module-info.class` definitions so the jar is also a proper Java module (JPMS). Jackson 2.12 and above include additional Gradle 6 Module Metadata for version alignment with Gradle. ----- # Use it! ## General Usage typically starts with creation of a reusable (and thread-safe, once configured) `JsonFactory` instance: ```java // Builder-style since 2.10: JsonFactory factory = JsonFactory.builder() // configure, if necessary: .enable(JsonReadFeature.ALLOW_JAVA_COMMENTS) .build(); // older 2.x mechanism, still supported for 2.x JsonFactory factory = new JsonFactory(); // configure, if necessary: factory.enable(JsonReadFeature.ALLOW_JAVA_COMMENTS); ``` Alternatively, you have an `ObjectMapper` (from [Jackson Databind package](https://github.com/FasterXML/jackson-databind)) handy; if so, you can do: ```java JsonFactory factory = objectMapper.getFactory(); ``` ## Usage, simple reading All reading is by using `JsonParser` (or its sub-classes, in case of data formats other than JSON), instance of which is constructed by `JsonFactory`. An example can be found from [Reading and Writing Event Streams](http://www.cowtowncoder.com/blog/archives/2009/01/entry_132.html) ## Usage, simple writing All writing is by using `JsonGenerator` (or its sub-classes, in case of data formats other than JSON), instance of which is constructed by `JsonFactory`: An example can be found from [Reading and Writing Event Streams](http://www.cowtowncoder.com/blog/archives/2009/01/entry_132.html) ## Processing limits Starting with [Jackson 2.15](https://github.com/FasterXML/jackson/wiki/Jackson-Release-2.15), Jackson has configurable limits for some aspects of input decoding and output generation. Implemented limits are: * Length are expressed in input/output units -- `byte`s or `char`s -- depending on input source * Defined as longest allowed length, but not necessarily imposed at 100% accuracy: that is, if maximum allowed length is specified as 1000 units, something with length of, say 1003 may not cause exception (but 1500 would typically do) * Defined using new `StreamReadConstraints` / `StreamWriteConstraints` classes, configurable on per-`JsonFactory` basis * Main focus is to reduce likelihood of excessive memory usage/retention and/or processing costs; not validation ### Input parsing limits * Maximum Number token length (2.15+): (see https://github.com/FasterXML/jackson-core/issues/815) * Default: Maximum 1000 for both integral and floating-point numbers. * Maximum String value length (2.15+): (see https://github.com/FasterXML/jackson-core/issues/863) * Default: 20_000_000 (20 million) (since 2.15.1; 2.15.0 had lower limit, 5 million) * Maximum Input nesting depth (2.15+): (see https://github.com/FasterXML/jackson-core/pull/943) * Default: 1000 levels * Maximum Property name length (2.16+): (see https://github.com/FasterXML/jackson-core/issues/1047) * Default: 50,000 * Maximum Document length (2.16+): (see https://github.com/FasterXML/jackson-core/issues/1046) * Default: Unlimited (-1) ### Output generation limits * Maximum Output nesting depth (2.16+): (see https://github.com/FasterXML/jackson-core/pull/1055) * Default: 1000 levels ### Re-configuring limits You can change per-factory limits as follows: ```java JsonFactory f = JsonFactory.builder() .streamReadConstraints(StreamReadConstraints.builder().maxDocumentLength(10_000_000L).build()) .streamReadConstraints(StreamReadConstraints.builder().maxNumberLength(250).build()) .streamWriteConstraints(StreamWriteConstraints.builder().maxNestingDepth(2000).build()) .build(); ``` ## Error Report Configuration Starting with [Jackson 2.16](https://github.com/FasterXML/jackson/wiki/Jackson-Release-2.16), Jackson offers configurable behavior around error-reporting. Currently supported configuration options are: - `maxErrorTokenLength` : Maximum length of token to include in error messages (2.16+): (see [#1066](https://github.com/FasterXML/jackson-core/issues/1066)) - `maxRawContentLength` : Maximum length of raw c