将solr响应（solrdocumentlist）转换为json（或xml）

Question

我正在进行搜索，尝试将HttpSolrServer的响应转换为json格式。答案是SolrDocumentList。我现在所拥有的代码是：

SolrQuery solrQuery = new SolrQuery(query); 
solrQuery.setParam("wt", "json"); //doesn't affect the return format 

QueryResponse rsp = solrServer.query(solrQuery); 
SolrDocumentList docs = rsp.getResults(); 

return docs.toString(); 

当我打印出来的回报，这回来为：

{numFound=2,start=0,docs=[SolrDocument{cat=[electronics, camera], features=[3x zoop, 7.1 megapixel Digital ELPH, movie clips up to 640x480 @30 fps, 2.0" TFT LCD, 118,000 pixels, built in flash, red-eye reduction], id=9885A004, inStock=true, includes=32MB SD card, USB cable, AV cable, battery, manu=Canon Inc., manufacturedate_dt=Mon Feb 13 10:26:37 EST 2006, name=Canon PowerShot SD500, popularity=7, price=329.95, store=45.17614,-93.87341, weight=6.4}, SolrDocument{cat=[electronics, multifunction printer, printer, scanner, copier], features=[Multifunction ink-jet color photo printer, Flatbed scanner, optical scan resolution of 1,200 x 2,400 dpi, 2.5" color LCD preview screen, Duplex Copying, Printing speed up to 29ppm black, 19ppm color, Hi-Speed USB, memory card: CompactFlash, Micro Drive, SmartMedia, Memory Stick, Memory Stick Pro, SD Card, and MultiMediaCard], id=0579B002, inStock=true, manu=Canon Inc., name=Canon PIXMA MP500 All-In-One Photo Printer, popularity=6, price=179.99, store=45.17614,-93.87341, weight=352.0}]}} 

使用他们的数据。例如在canon搜索。

如果我不是做return rsp.toString();我回来的头信息与它为：

{responseHeader={status=0,QTime=1,params={indent=true,q=canon\*,wt=xml,version=2.2}},response={numFound=2,start=0,docs=[SolrDocument{cat=[electronics, camera], features=[3x zoop, 7.1 megapixel Digital ELPH, movie clips up to 640x480 @30 fps, 2.0" TFT LCD, 118,000 pixels, built in flash, red-eye reduction], id=9885A004, inStock=true, includes=32MB SD card, USB cable, AV cable, battery, manu=Canon Inc., manufacturedate_dt=Mon Feb 13 10:26:37 EST 2006, name=Canon PowerShot SD500, popularity=7, price=329.95, store=45.17614,-93.87341, weight=6.4}, SolrDocument{cat=[electronics, multifunction printer, printer, scanner, copier], features=[Multifunction ink-jet color photo printer, Flatbed scanner, optical scan resolution of 1,200 x 2,400 dpi, 2.5" color LCD preview screen, Duplex Copying, Printing speed up to 29ppm black, 19ppm color, Hi-Speed USB, memory card: CompactFlash, Micro Drive, SmartMedia, Memory Stick, Memory Stick Pro, SD Card, and MultiMediaCard], id=0579B002, inStock=true, manu=Canon Inc., name=Canon PIXMA MP500 All-In-One Photo Printer, popularity=6, price=179.99, store=45.17614,-93.87341, weight=352.0}]}} 

我知道，与HttpSolrServer响应格式只能目前是XML或javabin（我已经设置为XML）的。这似乎对实际返回的结果及其格式没有影响。

我似乎无法找到任何有关将响应转换为json的信息。有任何想法吗？

Answer 1

虽然这是一个老问题，但我已经想出了一个类似的问题，在挖掘代码之后，我能够将响应转换为json，尽管我仍然对代码的速度和性能持怀疑态度情况下，存在过多的请求数来了..

所以下面的片的，我写代码（I用于从抛弃JSON lib和忽略的for循环笨结构）：

QueryResponse qp = server.query(solrQuery); 
SolrDocumentList docList= qp.getResults(); 
JSONObject returnResults = new JSONObject(); 
Map<Integer, Object> solrDocMap = new HashMap<Integer, Object>(); 
int counter = 1; 
for(Map singleDoc : docList) 
{ 
    solrDocMap.put(counter, new JSONObject(singleDoc)); 
    counter++; 
} 
returnResults.put("docs", solrDocMap); 

基本上这会让你在json中得到结果... solrj不允许你使用任何其他种类的javabin ，尽管你可能会在查询集重量明确

希望它有助于

Answer 2

对于你正在尝试做的事情，你不需要使用solrj库。您可以使用CommonsHTTPClient直接通过HTTP发送查询参数，并设置'wt = json' - 以JSON格式检索响应。

Answer 3

下面的代码工作

SolrDocumentList list = new SolrDocumentList(); 
JSONArray jArray =new JSONArray(); 
QueryResponse result = solr.query(parameters);   
list=result.getResults(); 

for (int i = 0; i < list.size(); i++) { 
    JSONObject json = new JSONObject(list.get(i)); 
    jArray.put(json);   
} 

还要添加参数json.nl=map。

来源：http://wiki.apache.org/solr/SolJSON

Answer 4

导入GSON和使用它的实用方法。