sth about solr and other opensource utils

luoson1

　　solr
　　1 drill data by random，eg.&random_123
　　solrQuery.addSortField("random_"+rand.nextInt(1000),SolrQuery.ORDER.desc);
　　
　　2  search id not equal to 222
　　eg.-id:222
　　
　　3 deleteById(List ids) in solrj
　　we should delete anything by id As much as possible,using deleteByQuery function may occur some problem.
　　
　　4 to get facet result we need to set facet and facet.field,also rows=0 is needed
　　
　　5 if you use dismax to search,you should use q="val" instead of q="title:val"
　　
　　6 highlight  params : &hl=true&hl.fl=title
　　
　　7 show score params :&fl=score ,useful  score will  spread out before us when you search some words
　　
　　8 delete url
　　update/?stream.body=mm&stream.contentType=text/xml;charset=utf-8&commit=true
　　
　　9 clear update docs
　　after we commit docs,we need to use "this.docs.clear()"  to clear the queue stored docs
　　
　　10 optimize
　　optimizing one time per day is a good choice
　　
　　11 get all the data which field value's length >0
　　q=fieldName:["" To *]
　　
　　12 use underline' can replace the default operator
　　SolrQuery.setParam("q.op", "OR");
　　
　　13 use dismax+qf to search instead of default text

　　14 url complex/analysis/field?q=param to get split words

　　15 if use mm, %25 is needed after urllink
　　
16 query with q only will get better performance than 'q&fq'
　　
　　json util
　　we often use net.sf.json and org.json.simple to help us do explaining,on use we found some string cannot  be decoded well by  net.sf.json ,
　　so  org.json.simple is good complement .After import org.json we may use JSONParser to change string to JSONObject.
　　　　For importing  net.sf.json,we may change list object to JSONArray,and decode json text to json object
　　and then use a function(JSONObject.toBean(jsonObj,className)) to convert jsonObj to class object