Java JsonEncoding类代码示例

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
@Override	//Object就是springmvc返回值
protected void writeInternal(Object object, HttpOutputMessage outputMessage) throws IOException,
        HttpMessageNotWritableException {
    // 从threadLocal中获取当前的Request对象
    HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder
            .currentRequestAttributes()).getRequest();
    
    String callbackParam = request.getParameter(callbackName);
    if (StringUtils.isEmpty(callbackParam)) {
        // 没有找到callback参数，直接返回json数据
        super.writeInternal(object, outputMessage);
    } else {
        JsonEncoding encoding = getJsonEncoding(outputMessage.getHeaders().getContentType());
        try {
        	//将对象转换为json串，然后用回调方法包括起来
            String result = callbackParam + "(" + super.getObjectMapper().writeValueAsString(object)
                    + ");";
            IOUtils.write(result, outputMessage.getBody(), encoding.getJavaName());
        } catch (JsonProcessingException ex) {
            throw new HttpMessageNotWritableException("Could not write JSON: " + ex.getMessage(), ex);
        }
    }

}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
private void _testFailOnWritingStringNotFieldName(JsonFactory f, boolean useReader) throws Exception
{
    JsonGenerator gen;
    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    if (useReader) {
        gen = f.createGenerator(ObjectWriteContext.empty(), new OutputStreamWriter(bout, "UTF-8"));
    } else {
        gen = f.createGenerator(ObjectWriteContext.empty(), bout, JsonEncoding.UTF8);
    }
    gen.writeStartObject();
    
    try {
        StringReader reader = new StringReader("a");
        gen.writeString(reader, -1);
        gen.flush();
        String json = bout.toString("UTF-8");
        fail("Should not have let "+gen.getClass().getName()+".writeString() be used in place of 'writeFieldName()': output = "+json);
    } catch (JsonProcessingException e) {
        verifyException(e, "can not write a String");
    }
    gen.close();
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
private void _testFailOnWritingStringFromReaderWithTooFewCharacters(JsonFactory f, boolean useReader) throws Exception{
    JsonGenerator gen;
    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    if (useReader) {
        gen = f.createGenerator(ObjectWriteContext.empty(), new OutputStreamWriter(bout, "UTF-8"));
    } else {
        gen = f.createGenerator(ObjectWriteContext.empty(), bout, JsonEncoding.UTF8);
    }
    gen.writeStartObject();

    try {
        String testStr = "aaaaaaaaa";
        StringReader reader = new StringReader(testStr);
        gen.writeFieldName("a");
        gen.writeString(reader, testStr.length() + 1);
        gen.flush();
        String json = bout.toString("UTF-8");
        fail("Should not have let "+gen.getClass().getName()+".writeString() ': output = "+json);
    } catch (JsonProcessingException e) {
        verifyException(e, "Didn't read enough from reader");
    }
    gen.close();
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
private void _testFailOnWritingStringFromNullReader(JsonFactory f, boolean useReader) throws Exception{
    JsonGenerator gen;
    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    if (useReader) {
        gen = f.createGenerator(ObjectWriteContext.empty(), new OutputStreamWriter(bout, "UTF-8"));
    } else {
        gen = f.createGenerator(ObjectWriteContext.empty(), bout, JsonEncoding.UTF8);
    }
    gen.writeStartObject();

    try {
        gen.writeFieldName("a");
        gen.writeString(null, -1);
        gen.flush();
        String json = bout.toString("UTF-8");
        fail("Should not have let "+gen.getClass().getName()+".writeString() ': output = "+json);
    } catch (JsonProcessingException e) {
        verifyException(e, "null reader");
    }
    gen.close();
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
private void _testDupFieldNameWrites(JsonFactory f, boolean useReader) throws Exception
{
    JsonGenerator gen;
    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    if (useReader) {
        gen = f.createGenerator(ObjectWriteContext.empty(), new OutputStreamWriter(bout, "UTF-8"));
    } else {
        gen = f.createGenerator(ObjectWriteContext.empty(), bout, JsonEncoding.UTF8);
    }
    gen.writeStartObject();
    gen.writeFieldName("a");
    
    try {
        gen.writeFieldName("b");
        gen.flush();
        String json = bout.toString("UTF-8");
        fail("Should not have let two consecutive field name writes succeed: output = "+json);
    } catch (JsonProcessingException e) {
        verifyException(e, "can not write a field name, expecting a value");
    }
    gen.close();
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
private void _testFailOnWritingStringNotFieldName(JsonFactory f, boolean useReader) throws Exception
{
    JsonGenerator gen;
    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    if (useReader) {
        gen = f.createGenerator(ObjectWriteContext.empty(), new OutputStreamWriter(bout, "UTF-8"));
    } else {
        gen = f.createGenerator(ObjectWriteContext.empty(), bout, JsonEncoding.UTF8);
    }
    gen.writeStartObject();
    
    try {
        gen.writeString("a");
        gen.flush();
        String json = bout.toString("UTF-8");
        fail("Should not have let "+gen.getClass().getName()+".writeString() be used in place of 'writeFieldName()': output = "+json);
    } catch (JsonProcessingException e) {
        verifyException(e, "can not write a String");
    }
    gen.close();
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
private void _testFailOnWritingFieldNameInRoot(JsonFactory f, boolean useReader) throws Exception
{
    JsonGenerator gen;
    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    if (useReader) {
        gen = f.createGenerator(ObjectWriteContext.empty(), new OutputStreamWriter(bout, "UTF-8"));
    } else {
        gen = f.createGenerator(ObjectWriteContext.empty(), bout, JsonEncoding.UTF8);
    }
    try {
        gen.writeFieldName("a");
        gen.flush();
        String json = bout.toString("UTF-8");
        fail("Should not have let "+gen.getClass().getName()+".writeFieldName() be used in root context: output = "+json);
    } catch (JsonProcessingException e) {
        verifyException(e, "can not write a field name");
    }
    gen.close();
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
public GenericJacksonWayGraphOutputFormat(ISegmentOutputFormat<T> segmentOutputFormat, 
		IAdapter<IGraphVersionMetadataDTO, IWayGraphVersionMetadata> adapter,
		OutputStream stream, 
		JsonGenerator generator)
{
	this.segmentOutputFormat = segmentOutputFormat;
	this.adapter = adapter;
	if (generator == null) {
		try {
			this.generator = new MappingJsonFactory().createGenerator(stream, JsonEncoding.UTF8);
			this.generator.useDefaultPrettyPrinter();
		} catch (IOException e) {
			log.error("error creating jackson json factory", e);
		}
	} else {
		this.generator = generator;
	}
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
public GenericJacksonSegmentOutputFormat(ISegmentAdapterRegistry<? extends IBaseSegmentDTO, T> adapterRegistry,
		OutputStream stream, JsonGenerator generator, int flushBatchCount)
{
	this.adapterRegistry = adapterRegistry;
	if (generator == null) {
		try {
			this.generator = new MappingJsonFactory().createGenerator(new BufferedOutputStream(stream), JsonEncoding.UTF8);
			this.generator.useDefaultPrettyPrinter();
		} catch (IOException e) {
			log.error("error creating jackson json factory", e);
		}
	}
	if (flushBatchCount > 0 ) {
		this.flushBatchCount = flushBatchCount;
	} else {
		log.warn("flushBatchCount ignored, can not be negative or 0");
	}
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
private String buildJSONFromFields(Collection<SearchHitField> values) {
	JsonFactory nodeFactory = new JsonFactory();
	try {
		ByteArrayOutputStream stream = new ByteArrayOutputStream();
		JsonGenerator generator = nodeFactory.createGenerator(stream, JsonEncoding.UTF8);
		generator.writeStartObject();
		for (SearchHitField value : values) {
			if (value.getValues().size() > 1) {
				generator.writeArrayFieldStart(value.getName());
				for (Object val : value.getValues()) {
					generator.writeObject(val);
				}
				generator.writeEndArray();
			} else {
				generator.writeObjectField(value.getName(), value.getValue());
			}
		}
		generator.writeEndObject();
		generator.flush();
		return new String(stream.toByteArray(), Charset.forName("UTF-8"));
	} catch (IOException e) {
		return null;
	}
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
public String getJSON() {
  JsonFactory jf = new JsonFactory();
  // OutputStream os = new ByteArrayOutputStream();
  HeapDataOutputStream hdos = new HeapDataOutputStream(org.apache.geode.internal.Version.CURRENT);
  try {
    JsonGenerator jg = jf.createJsonGenerator(hdos, JsonEncoding.UTF8);
    enableDisableJSONGeneratorFeature(jg);
    getJSONString(jg, m_pdxInstance);
    jg.close();
    return new String(hdos.toByteArray());
  } catch (IOException e) {
    throw new RuntimeException(e.getMessage());
  } finally {
    hdos.close();
  }
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
/**
 * Check whether the encoding is valid.
 * @param in input of bytes
 * @throws IOException this is an IO exception
 * @throws UnsupportedException this is an unsupported exception
 */
private static void checkEncoding(ByteBuf in) throws IOException {
    int inputStart = 0;
    int inputLength = 4;
    fliterCharaters(in);
    byte[] buff = new byte[4];
    in.getBytes(in.readerIndex(), buff);
    ByteSourceJsonBootstrapper strapper = new ByteSourceJsonBootstrapper(new IOContext(new BufferRecycler(),
                                                                                       null,
                                                                                       false),
                                                                         buff, inputStart,
                                                                         inputLength);
    JsonEncoding jsonEncoding = strapper.detectEncoding();
    if (!JsonEncoding.UTF8.equals(jsonEncoding)) {
        throw new UnsupportedException("Only UTF-8 encoding is supported.");
    }
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
/**
 * Serialises the {@link DecisionTreeRuleSet} into the {@link OutputStream} in Json format.
 *
 * <p>Any exceptions are wrapped and thrown via the {@link EhSupport} API.
 *
 * @param out     {@link OutputStream} to write into
 * @param ruleSet {@link DecisionTreeRuleSet} to serialise
 */
public static void toJsonWriter(final OutputStream out, final DecisionTreeRuleSet ruleSet) {
    EhSupport.propagate(() -> {
        try (JsonGenerator generator = new JsonFactory().createGenerator(out, JsonEncoding.UTF8)) {
            generator.useDefaultPrettyPrinter();
            generator.writeStartObject();
            generator.writeStringField("name", ruleSet.getName());
            writeRuleSetDrivers(generator, ruleSet);
            writeRuleSetGroups(generator, ruleSet.getValueGroups());
            writeRules(generator, ruleSet);

            generator.writeEndObject();
            generator.flush();
        }
    });
}
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
private String buildJSONFromFields(Collection<SearchHitField> values) {
JsonFactory nodeFactory = new JsonFactory();
try {
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    JsonGenerator generator = nodeFactory.createGenerator(stream, JsonEncoding.UTF8);
    generator.writeStartObject();
    for (SearchHitField value : values) {
	if (value.getValues().size() > 1) {
	    generator.writeArrayFieldStart(value.getName());
	    for (Object val : value.getValues()) {
		generator.writeObject(val);
	    }
	    generator.writeEndArray();
	} else {
	    generator.writeObjectField(value.getName(), value.getValue());
	}
    }
    generator.writeEndObject();
    generator.flush();
    return new String(stream.toByteArray(), Charset.forName("UTF-8"));
} catch (IOException e) {
    LOG.error("IOException in buildJSONFromFields ", e);
    return null;
}
   }
 

import com.fasterxml.jackson.core.JsonEncoding; //导入依赖的package包/类
public Response getQueryResult(final Query query) {
	StreamingOutput stream = new StreamingOutput() {
		@Override
		public void write( OutputStream os ) throws IOException, WebApplicationException {
			JsonGenerator jg = objectMapper.getFactory().createGenerator(os, JsonEncoding.UTF8);
			jg.setPrettyPrinter(new DefaultPrettyPrinter());
			jg.writeStartObject();
			if (query != null && query.toCypher().length() > 0) {
				writeQueryDetails(jg, query);
				System.out.println(query.toCypher());
				executeQuery(jg, query);
			} else {
				jg.writeStringField("error", "No query supplied.");
			}
			jg.writeEndObject();
			jg.flush();
			jg.close();
		}
	};

	return Response.ok().entity( stream ).type( MediaType.APPLICATION_JSON ).build();
}