cassandra 学习笔记

12)//插入一个superColumn元素
    //不含有内容的superColumn不能同过该方法被创建,会抛出异常

1.  
2.     public void test_batch_insert_super_t()
3.     {
4.         try {
5.              tableName    = "Table1";
6.              keyName        = "superkeytest";
7.              superColumnFamilyName = "Super1";
8.             //产生1个superColumn元素
9.             //首先产生1个column_t的list
10.             List Clist = new ArrayList();
11.             //当两个名字一样的时候，先前的会被覆盖
12.             Clist.add(newcolumn_t("stardcolumninsuper1","stardcolumn1".getBytes(),.currentTimeMillis()));
13.             Clist.add(newcolumn_t("stardcolumninsuper2","stardcolumn2".getBytes(),.currentTimeMillis()));
14.             //产生一个superColumn元素
15.              superColumnName = "superColumn3";
16.             superColumn_t sct = new superColumn_t(superColumnName , Clist);
17.             //将这个元素装入到一个superColumn_t的List中
18.             List SClist = new ArrayList();
19.             SClist.add(sct);
20.             //将这个super_column 的list连同对应的superColumnFamily的名字一起放入一个hashmap中
21.             Map> cfmap = new HashMap>();
22.             cfmap.put(superColumnFamilyName, SClist);
23.             //区别于一般的，这里要求的column元素是superColumn元素
24.             //将整理好的信息关联一个key后生成一个mutation
25.             batch_mutation_super_t bmst = newbatch_mutation_super_t(tableName,keyName,cfmap);
26.             boolean block = true;
27.             //执行这个mutation的插入操作
28.             cli.batch_insert_superColumn(bmst, block);
29.         } catch (InvalidRequestException e) {
30.             e.printStackTrace();
31.         } catch (UnavailableException e) {
32.             e.printStackTrace();
33.         } catch (TException e) {
34.             e.printStackTrace();
35.         }
36.     }
37.  

13)//获取一个SuperColumn中的信息

1.  
2.     public void test_get_superColumn()
3.     {
4.          tableName = "Table1";
5.          keyName = "superkeytest";
6.          superColumnFamilyName = "Super1";
7.          superColumnName = "superColumn3";
8.          path = superColumnFamilyName+":"+superColumnName;
9.         try {
10.             superColumn_t sct = cli.get_superColumn(tableName, keyName, path);
11.             if(sct != null){
12.                 .out.println("Super Name : "+sct.getName());
13.                 .out.println("Size : "+sct.getColumnsSize());
14.                 List clist = sct.getColumns();
15.             }else{
16.                 .out.println("super column is empty");
17.             }
18.         } catch (InvalidRequestException e) {
19.             e.printStackTrace();
20.         } catch (NotFoundException e) {
21.             e.printStackTrace();
22.         } catch (TException e) {
23.             e.printStackTrace();
24.         } catch ( e) {
25.             e.printStackTrace();
26.         }
27.     }
28.  

14)//尝试向一个superColumn中添加column元素(就是column_t对象)
   //注意：想superColumnFamily中添加一般的column元素是不被允许的,所以superColumnFamliy中只能有superColumn，而superColumn中只能有一般的column
   //而一般的columnFamily中也只能有一般的column

1.  
2.     public void test_insert_standard_to_super()
3.     {
4.          tableName = "Table1";
5.          keyName = "superkeytest";
6.          superColumnFamily = "Super1";
7.          superColumnName = "superColumn1";
8.          columnName = "normal_column";
9.          value = "normal_column_value_add";
10.          path = superColumnFamily+":"+superColumnName+":"+columnName;
11.         try {
12.             cli.insert(tableName, keyName, path, value.getBytes(),.currentTimeMillis(), true);
13.             //尝试取出这个元素并显示这个元素
14.             column_t cmt = cli.get_column(tableName, keyName, path);
15.             if(cmt != null){
16.                 .out.println("column name : "+cmt.getColumnName());
17.                 .out.println("column value: "+new(cmt.getValue(),"UTF-8"));
18.                 .out.println("column time : "+cmt.getTimestamp()+"\n");
19.             }else{
20.                 .out.println("column is empty");
21.             }
22.         } catch (InvalidRequestException e) {
23.             e.printStackTrace();
24.         } catch (UnavailableException e) {
25.             e.printStackTrace();
26.         } catch (TException e) {
27.             e.printStackTrace();
28.         } catch (NotFoundException e) {
29.             e.printStackTrace();
30.         } catch ( e) {
31.             e.printStackTrace();
32.         }
33.     }
34.  

15)//术语解释：每个key都对应一个Row的信息这个Row的信息又按照columnFamliy 或superColumnFamily分成了很多slice
    //同针对一般的columnFamliy类似,这个方法是获取给定key的某个superColumnFamily的slice，这个slice中的元素都是superColumn

1.  
2.     public void test_get_slice_super()
3.     {
4.          tableName = "Table1";
5.          keyName = "superkeytest";
6.          superColumnFamily = "Super1";
7.         try {
8.             List sct = cli.get_slice_super(tableName, keyName, superColumnFamily, 0, 10);
9.         } catch (InvalidRequestException e) {
10.             e.printStackTrace();
11.         } catch (TException e) {
12.             e.printStackTrace();
13.         } catch ( e) {
14.             e.printStackTrace();
15.         }
16.     }
17.