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1、Springmvc 组合jackson与fastjson使用心得Springmvc 组合jackson与fastjson使用心得 1、解决方案 可以将其中的main方法删掉。测试用的。我测试的结果是，jackson比fastjson快。 fastjson是1.1.36 jackson是2.2.3 jdk是1.7.40，client cpu是intel i3 2、主要代码 package org.springframework.web.servlet.view.json; import java.io.ByteArrayOutputStream; import java.io.IOExcepti
2、on; import java.io.OutputStream; import java.io.StringReader; import java.io.StringWriter; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; import javax.servlet.http
3、.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.util.CollectionUtils; import org.springframework.validation.BindingResult; import org.springframework.web.servlet.view.AbstractView; import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.parser.Fea
4、ture; import com.alibaba.fastjson.serializer.SerializerFeature; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackso
5、n.core.type.TypeReference; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.MappingIterator; import com.fasterxml.jackson.databind.ObjectMapper; import mon.collect.Lists; import mon.collect.Maps; import mon.collect.Sets; import com.test.User; public c
6、lass MappingFastJsonView extends AbstractView /* * Default content type: application/json. * Overridable through link #setContentType. */ public static final String DEFAULT_CONTENT_TYPE = application/json; private String encoding = UTF-8; private String jsonPrefix; private Boolean prettyPrint; priva
7、te Set modelKeys; private boolean extractValueFromSingleKeyModel = false; private boolean disableCaching = true; private boolean updateContentLength = false; /* * Construct a new code MappingFastJsonView, setting the content type to code application/json. */ public MappingFastJsonView setContentType
8、(DEFAULT_CONTENT_TYPE); setExposePathVariables(false); public String getEncoding return encoding; public void setEncoding(String encoding) this.encoding = encoding; /* * Specify a custom prefix to use for this views JSON output. * Default is none. * see #setPrefixJson */ public void setJsonPrefix(St
9、ring jsonPrefix) this.jsonPrefix = jsonPrefix; /* * Indicates whether the JSON output by this view should be prefixed with & . * Default is code false. * Prefixing the JSON string in this manner is used to help prevent JSON Hijacking. * The prefix renders the string syntactically invalid as a script
10、 so that it cannot be hijacked. * This prefix does not affect the evaluation of JSON, but if JSON validation is performed * on the string, the prefix would need to be ignored. * see #setJsonPrefix */ public void setPrefixJson(boolean prefixJson) / if (prefixJson) / if (jsonPrefix = null) / jsonPrefi
11、x = & ; / / this.jsonPrefix = (prefixJson ? & : null); /* * Whether to use the default pretty printer when writing JSON. * This is a shortcut for setting up an code JSON * The default value is code false. */ public void setPrettyPrint(boolean prettyPrint) this.prettyPrint = prettyPrint; /* * Set the
12、 attribute in the model that should be rendered by this view. * When set, all other model attributes will be ignored. */ public void setModelKey(String modelKey) this.modelKeys = Collections.singleton(modelKey); /* * Set the attributes in the model that should be rendered by this view. * When set, a
13、ll other model attributes will be ignored. */ public void setModelKeys(Set modelKeys) this.modelKeys = modelKeys; /* * Return the attributes in the model that should be rendered by this view. */ public final Set getModelKeys return this.modelKeys; /* * Set whether to serialize models containing a si
14、ngle attribute as a map or whether to * extract the single value from the model and serialize it directly. * The effect of setting this flag is similar to using code MappingJacksonHttpMessageConverter * with an code ResponseBody request-handling method. * Default is code false. */ public void setExt
15、ractValueFromSingleKeyModel(boolean extractValueFromSingleKeyModel) this.extractValueFromSingleKeyModel = extractValueFromSingleKeyModel; /* * Disables caching of the generated JSON. * Default is code true, which will prevent the client from caching the generated JSON. */ public void setDisableCachi
16、ng(boolean disableCaching) this.disableCaching = disableCaching; /* * Whether to update the Content-Length header of the response. When set to * code true, the response is buffered in order to determine the content * length and set the Content-Length header of the response. * The default setting is
17、code false. */ public void setUpdateContentLength(boolean updateContentLength) this.updateContentLength = updateContentLength; Override protected void prepareResponse(HttpServletRequest request, HttpServletResponse response) setResponseContentType(request, response); response.setCharacterEncoding(en
18、coding); if (this.disableCaching) response.addHeader(Pragma, no-cache); response.addHeader(Cache-Control, no-cache, no-store, max-age=0); response.addDateHeader(Expires, 1L); Override protected void renderMergedOutputModel(Map model, HttpServletRequest request, HttpServletResponse response) throws E
19、xception OutputStream stream = (this.updateContentLength ? createTemporaryOutputStream : response.getOutputStream); Object value = filterModel(model); writeContent(stream, value, this.jsonPrefix); if (this.updateContentLength) writeToResponse(response, (ByteArrayOutputStream) stream); /* * Filter ou
20、t undesired attributes from the given model. * The return value can be either another link Map or a single value object. * The default implementation removes link BindingResult instances and entries * not included in the link #setRenderedAttributes renderedAttributes property. * param model the mode
21、l, as passed on to link #renderMergedOutputModel * return the value to be rendered */ protected Object filterModel(Map model) Map result = new HashMap(model.size); Set renderedAttributes = (!CollectionUtils.isEmpty(this.modelKeys) ? this.modelKeys : model.keySet); for (Map.Entry entry : model.entryS
22、et) if (!(entry.getValue instanceof BindingResult) & renderedAttributes.contains(entry.getKey) result.put(entry.getKey, entry.getValue); return (this.extractValueFromSingleKeyModel & result.size = 1 ? result.values.iterator.next : result); /* * Write the actual JSON content to the stream. * param st
23、ream the output stream to use * param value the value to be rendered, as returned from link #filterModel * param jsonPrefix the prefix for this views JSON output * (as indicated through link #setJsonPrefix/link #setPrefixJson) * throws IOException if writing failed */ protected void writeContent(Out
24、putStream stream, Object value, String jsonPrefix) throws IOException List list = new ArrayList; if (prettyPrint != null & prettyPrint) list.add(SerializerFeature.PrettyFormat); SerializerFeature features = new SerializerFeaturelist.size; list.toArray(features); byte jsonBytes = JSON.toJSONBytes(val
25、ue, features); if (jsonPrefix != null) /此处亦可字符串相加，然后转成字节数组 byte prefixBytes = jsonPrefix.getBytes(Charset.forName(UTF-8); int prefixLength = prefixBytes.length; int jsonLength = jsonBytes.length; byte finalJsonBytes = new byteprefixLength + jsonLength; System.arraycopy(prefixBytes, 0, finalJsonBytes
26、, 0, prefixLength); System.arraycopy(jsonBytes, 0, finalJsonBytes, prefixLength, jsonLength); stream.write(finalJsonBytes); else stream.write(jsonBytes); stream.flush; public static void main(String args) List users = Lists.newArrayList; for (int j = 0; j 10; j+) User value = new User; value.setAddr
27、ess(asdfjklasdjf); value.setAge(22); value.setGender(1); value.setPassword(jkljklj); value.setUserName(); List strList = Lists.newArrayList; Map strMap = Maps.newHashMap; Set setInt = Sets.newHashSet; for (int i = 0; i 10; i+) strList.add(a + i); strMap.put(a + i, a + i); setInt.add(i); value.setSet
28、Int(setInt); value.setStrList(strList); value.setStrMap(strMap); users.add(value); int times = 1; / long d = System.currentTimeMillis; / String jsonPrefix = aaa; / / for (int i = 0; i times; i+) / byte jsonBytes = JSON.toJSONBytes(value); / byte prefixBytes = jsonPrefix.getBytes(Charset.forName(UTF-
29、8); / int prefixLength = prefixBytes.length; / int jsonLength = jsonBytes.length; / byte finalJsonBytes = new byteprefixLength + jsonLength; / / System.arraycopy(prefixBytes, 0, finalJsonBytes, 0, prefixLength); / System.arraycopy(jsonBytes, 0, finalJsonBytes, prefixLength, jsonLength); / / System.o
30、ut.println(System.currentTimeMillis - d); String json = ; String json2 = ; long d2 = System.currentTimeMillis; /String jsonPrefix2 = aaa; for (int i = 0; i times; i+) json = JSON.toJSONString(users); / jsonBytes = jsonPrefix2 + jsonBytes; / / byte prefixBytes = jsonBytes.getBytes(Charset.forName(UTF
31、-8); System.out.println(fastjson parser : + (System.currentTimeMillis - d2); ObjectMapper mapper = new ObjectMapper; /org.codehaus.jackson.map.ObjectMapper mapper = new org.codehaus.jackson.map.ObjectMapper; long d3 = System.currentTimeMillis; /String jsonPrefix3 = aaa; for (int i = 0; i times; i+)
32、/String jsonBytes = null; try /StringWriter writer = new StringWriter; /JsonGenerator generator = new JsonFactory.createGenerator(writer); /mapper.writeValue(writer, value); /jsonBytes = writer.toString; json2 = mapper.writeValueAsString(users); /mapper.readValue(new StringReader(), class1); catch (
33、Exception e) e.printStackTrace; / jsonBytes = jsonPrefix3 + jsonBytes; / / byte prefixBytes = jsonBytes.getBytes(Charset.forName(UTF-8); System.out.println(jackson parser : + (System.currentTimeMillis - d3); long d5 = System.currentTimeMillis; for (int i = 0; i times; i+) JSON.parseArray(json, User.
34、class); System.out.println(fastjson deserializer : + (System.currentTimeMillis - d5); long d4 = System.currentTimeMillis; for (int i = 0; i times; i+) try /List userList = Lists.newArrayList; mapper.readValue(json2, new TypeReferenceList ); / List userList = Lists.newArrayList; / for (;iterator.hasN
35、ext;) / userList.add(iterator.nextValue); / /System.out.println(userList); catch (JsonParseException e) e.printStackTrace; catch (JsonMappingException e) e.printStackTrace; catch (IOException e) e.printStackTrace; System.out.println(jackson deserializer : + (System.currentTimeMillis - d4); package c
36、om.test; import java.util.List; import java.util.Map; import java.util.Set; import javax.xml.bind.annotation.XmlRootElement; XmlRootElement public class User private String userName; private String address; private int age; private int gender; private String password; private List strList; private M
37、ap strMap; private Set setInt; public String getUserName return userName; public void setUserName(String userName) this.userName = userName; public String getAddress return address; public void setAddress(String address) this.address = address; public int getAge return age; public void setAge(int age) this.age = age; public int getGender return gender; public void setGender(int gender) this.gender = gender; public String getPassword return password;
