我有一个非常大的Json,需要进行流传输和解析。来源看起来像这样:
{
"Report_Entry": [{
"FirstName": "Brett",
"Position": "13_Delta Corp",
"Worker": "Mr Battles"
},
{
"FirstName": "Dan",
"Position": "13_Delta Corp",
"Worker": "Mr Brown"
}]
}
我想做这样的事情:
InputStream inStream = null;
JsonReader reader = null;
Gson gson = null;
gson = new Gson();
inStream = new FileInputStream("C:\\Downloads\\largereportdata.json");
reader = new JsonReader(new InputStreamReader(inStream, "UTF-8"));
List<Message> messages = new ArrayList<Message>();
reader.beginArray();
while (reader.hasNext()) {
Message message = gson.fromJson(reader, Message.class);
//Process the message
}
reader.endArray();
reader.close();
class Message{
public String First_Name = null;
public String Position = null;
public String Worker = null;
}
如果我使用gson.fromJson作为数组的父json对象,那么整个对象将被装入包含数组的ONE对象中,但是我想将数组流式输出。
我现在看到的唯一方法是以某种方式编辑输入并删除父级“ Report_Entry”和大括号,这是一种糟糕的方法。
有更好的方法吗?
不幸的是,源无法更改,我必须对此进行处理。
谢谢! 丹尼尔
答案 0 :(得分:0)
我使用Jackson API解决了它。
JsonFactory f = new MappingJsonFactory();
JsonParser jp = new JsonFactory().createParser(new File("C:\\Users\\Downloads\\rootpart.json"));
ObjectMapper mapper = new ObjectMapper();
ReportData reportData = null;
JsonToken current;
current = jp.nextToken();
if (current != JsonToken.START_OBJECT) {
System.out.println("Error: root should be object: quitting.");
return;
}
while (jp.nextToken() != JsonToken.END_OBJECT) {
String fieldName = jp.getCurrentName();
current = jp.nextToken();
if (fieldName.equals("Report_Entry")) {
if (current == JsonToken.START_ARRAY) {
while (current != JsonToken.END_ARRAY) {
if (current == JsonToken.START_OBJECT) {
reportData = mapper.readValue(jp, ReportData.class);
System.out.println(reportData.getKey());
}
current = jp.nextToken();
}
} else {
jp.skipChildren();
}
} else {
jp.skipChildren();
}
}
谢谢!