我有以下用例：
我必须将“标题”：“G103 MMath数学（4年）”写成一个Json字符串，它构成了一个更大的Json树的一部分：
{
"dimensions": [
"www.southampton.ac.uk/maths/undergraduate/courses/g100_mathematics.page",
"\"People Also Viewed\""
],
"metrics": [
{
"values": [
"1275"
]
}
]
},
Json必须变成这样：
{
"dimensions": [
"www.southampton.ac.uk/maths/undergraduate/courses/g103_mmath.page",
"\"People Also Viewed\""
],
"title": "G103 MMath Mathematics (4 years)",
"metrics": [
{
"values": [
"105"
]
}
]
}
我现在正在使用Java 6（将在不久的将来成为Java 8）。我已经回顾了Gson和Jackson，并了解到还有Boon。我试图在Gson中这样做，并且无法弄清楚如何在不创建Pojos的情况下读取Json String（使用http://www.jsonschema2pojo.org/）。所以我决定使用Jackson 2.5.1。我得到了一点，我可以在那里创建一个Json漂亮的TokenBuffer，我可以将从Json String读取的树写入一个新文件。
以下是方法：
/**
* Generates Json from original Google Analytics report to include extra data on each page.
* @param json input Json String
* @return output returns the converted Json
* @throws IOException when the File cannot be read
*/
public String generateJson(String json) throws IOException {
String output;
//Create a JsonGenerator
ObjectMapper mapper = new ObjectMapper();
JsonParser parser = mapper.getFactory().createParser(json);
TokenBuffer buffer = parser.readValueAs(TokenBuffer.class);
JsonGenerator gen = mapper
.getFactory()
.createGenerator(new File("/Users/arnout/dev/southampton/sitepublisher.git/soton-test/workarea/resultJson.json"), JsonEncoding.UTF8);
gen
.useDefaultPrettyPrinter()
.writeObject(buffer);
// read json in buffer back as tree
JsonNode root = mapper.readTree(buffer.asParser());
JsonNode dimensions = null;
log.debug("GoogleAnalyticsGenerator --- generateJson -- Jackson generated json in TokenBuffer is " + root );
int count = root.get("reports").get(0).get("data").get("rows").size();
for ( int i = 0; i < count ; i++ ){
dimensions = root.get("reports").get(0).get("data").get("rows").get(i).get("dimensions");
log.debug("GoogleAnalyticsGenerator --- generateJson -- Jackson root dimension array is " + dimensions );
}
gen.close();
parser.close();
//Close the JsonGenerator
output = json.toString();
return output;
}
}
目前，当我在此方法上运行单元测试时，我返回了Json缓冲区，我可以返回JsonNode维度（来自Google Analytics的结果）。
5165 [main] DEBUG u.a.s.l.g.a.GoogleAnalyticsGenerator - GoogleAnalyticsGenerator --- generateJson -- Jackson generated json in TokenBuffer is {"reports":[{"columnHeader":{"dimensions": ["ga:pagePath","ga:segment"],"metricHeader":{"metricHeaderEntries":[{"name":"pageviews","type":"INTEGER"}]}},"data":{"maximums":[{"values":["1356"]}],"minimums":[{"values":["2"]}],"rowCount":150,"rows":[{"dimensions":["www.southampton.ac.uk/maths/undergraduate/courses/g100_mathematics.page","\"People Also Viewed\""],"metrics":[{"values":["1356"]}]},{"dimensions":["www.southampton.ac.uk/maths/undergraduate/courses/g103_mmath.page","\"People Also Viewed\""],"metrics":[{"values":["105"]}]},{"dimensions":["www.southampton.ac.uk/maths/undergraduate/courses/g120_mathematical_studies.page","\"People Also Viewed\""],"metrics":[{"values":["103"]}]},{"dimensions":["www.southampton.ac.uk/maths/undergraduate/courses/g1nh_maths_with_finance.page","\"People Also Viewed\""],"metrics":[{"values":["73"]}]},{"dimensions":["www.southampton.ac.uk/maths/undergraduate/courses/g1n3_maths_with_actuarial_science.page","\"People Also Viewed\""],"metrics":[{"values":["69"]}]},{"dimensions":["www.southampton.ac.uk/maths/undergraduate/courses/g1g3_maths_with_statistics.page","\"People Also Viewed\""],"metrics":[{"values":["50"]}]}],"samplesReadCounts":["488083"],"samplingSpaceSizes":["867358"],"totals":[{"values":["2557"]}]},"nextPageToken":"6"}]}
5165 [main] DEBUG u.a.s.l.g.a.GoogleAnalyticsGenerator - GoogleAnalyticsGenerator --- generateJson -- Jackson root dimension array is ["www.southampton.ac.uk/maths/undergraduate/courses/g100_mathematics.page","\"People Also Viewed\""]
5165 [main] DEBUG u.a.s.l.g.a.GoogleAnalyticsGenerator - GoogleAnalyticsGenerator --- generateJson -- Jackson root dimension array is ["www.southampton.ac.uk/maths/undergraduate/courses/g103_mmath.page","\"People Also Viewed\""]
5165 [main] DEBUG u.a.s.l.g.a.GoogleAnalyticsGenerator - GoogleAnalyticsGenerator --- generateJson -- Jackson root dimension array is ["www.southampton.ac.uk/maths/undergraduate/courses/g120_mathematical_studies.page","\"People Also Viewed\""]
5165 [main] DEBUG u.a.s.l.g.a.GoogleAnalyticsGenerator - GoogleAnalyticsGenerator --- generateJson -- Jackson root dimension array is ["www.southampton.ac.uk/maths/undergraduate/courses/g1nh_maths_with_finance.page","\"People Also Viewed\""]
5166 [main] DEBUG u.a.s.l.g.a.GoogleAnalyticsGenerator - GoogleAnalyticsGenerator --- generateJson -- Jackson root dimension array is ["www.southampton.ac.uk/maths/undergraduate/courses/g1n3_maths_with_actuarial_science.page","\"People Also Viewed\""]
5166 [main] DEBUG u.a.s.l.g.a.GoogleAnalyticsGenerator - GoogleAnalyticsGenerator --- generateJson -- Jackson root dimension array is ["www.southampton.ac.uk/maths/undergraduate/courses/g1g3_maths_with_statistics.page","\"People Also Viewed\""]
我的问题是如何添加标题？
如果更快/更容易（或任何其他平台），我很乐意使用Gson或Boon。
答案 0 :(得分：0)
我在Jackson 2上实现了序列化，因为我测试了Json元素＆＃34;行＆＃34;毕竟实际上永远不会改变。以下是我参考的内容：
/**
* Generates Json from original Google Analytics report to include extra data on each page.
* @return output returns the converted Json
* @throws IOException when the File cannot be read
*/
public void generateJson(File input) throws IOException {
try {
//Convert object to JSON string and pretty print.
ObjectMapper mapper = new ObjectMapper();
//read the retrieved Json values into the Object members.
GoogleAnalyticsJsonObject gao = mapper.readValue(input, GoogleAnalyticsJsonObject.class);
String json = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(gao);
JsonParser parser = mapper.getFactory().createParser(json);
TokenBuffer buffer = parser.readValueAs(TokenBuffer.class);
//Regenerate the Json file.
JsonGenerator gen = mapper.getFactory().createGenerator(
new File(String.valueOf(input)), JsonEncoding.UTF8);
gen.useDefaultPrettyPrinter().writeObject(buffer);
//Close the JsonGenerator.
gen.close();
parser.close();
} catch (JsonGenerationException jge) {
log.error("JsonGenerationException " + jge);
}
}
我创建了一个序列化的包，并放入了我从jsonschema2pojo生成的所有Pojos，并添加了一个名为Title的新Object。我像这样添加了对象：
@JsonInclude(JsonInclude.Include.ALWAYS)
@JsonPropertyOrder（{ ＆＃34;尺寸＆＃34 ;, ＆＃34;标题＆＃34 ;, ＆＃34;度量＆＃34; }） 公共类Row {
@JsonProperty("dimensions")
private List<String> dimensions = null;
@JsonProperty("title")
private String title = null;
@JsonProperty("metrics")
private List<Metric> metrics = null;
@JsonIgnore
private Map<String, Object> additionalProperties = new HashMap<String, Object>();
// Set a Sl4J logger
private final Logger log = LoggerFactory.getLogger(Row.class);
/**
*
* @return
* The title
*/
@JsonProperty("title")
public String getTitle() {
String result = "";
//generate the title from the Page
//page title for this item
//get the associated content
//read out the content fields for : Code, Name, Award, Duration with some conditional logic
List<String> dimensions = getDimensions();
String pageTitle = "";
Title title = new Title();
for ( String dim : dimensions ) {
if ( dim.startsWith("www")) { //filter out the views from the dimensions, leaving us with page URLs
try {
result = title.getTitle(dim);
} catch (FileManagerException e) {
e.printStackTrace();
}
}
}
return result;
}
/**
*
* @param title
* The title
*/
@JsonProperty("title")
public void setTitle(String title) {
this.title = title;
}
/**
*
* @return
* The dimensions
*/
@JsonProperty("dimensions")
public List<String> getDimensions() {
return dimensions;
}
/**
*
* @param dimensions
* The dimensions
*/
@JsonProperty("dimensions")
public void setDimensions(List<String> dimensions) {
this.dimensions = dimensions;
}
/**
*
* @return
* The metrics
*/
@JsonProperty("metrics")
public List<Metric> getMetrics() {
return metrics;
}
/**
*
* @param metrics
* The metrics
*/
@JsonProperty("metrics")
public void setMetrics(List<Metric> metrics) {
this.metrics = metrics;
}
@JsonAnyGetter
public Map<String, Object> getAdditionalProperties() {
return this.additionalProperties;
}
@JsonAnySetter
public void setAdditionalProperty(String name, Object value) {
this.additionalProperties.put(name, value);
}
}