guava table

1、guava的table类，可代替map>,使用非常方便。

import com.google.common.collect.HashBasedTable;
import com.google.common.collect.Table;
import java.util.Map;
import java.util.Set;

public class Test03 {
    public static void main(String[] args) {
        Table employeeTable = HashBasedTable.create();
        employeeTable.put("IBM", "101", "Mahesh");
        employeeTable.put("IBM", "102", "Ramesh");
        employeeTable.put("IBM", "103", "Suresh");

        employeeTable.put("Microsoft", "111", "Sohan");
        employeeTable.put("Microsoft", "112", "Mohan");
        employeeTable.put("Microsoft", "113", "Rohan");

        employeeTable.put("TCS", "121", "Ram");
        employeeTable.put("TCS", "102", "Shyam");
        employeeTable.put("TCS", "123", "Sunil");

        //返回所有行数据
        System.out.println(employeeTable.cellSet());

        //返回所有公司
        System.out.println(employeeTable.rowKeySet());

        //返回所有员工编号
        System.out.println(employeeTable.columnKeySet());

        //返回所有员工姓名
        System.out.println(employeeTable.values());

        //公司中的所有员工和员工编号
        System.out.println(employeeTable.rowMap());

        //员工编号对应的公司和员工名称
        System.out.println(employeeTable.columnMap());

        //IBM公司中所有信息
        Map ibmEmployees = employeeTable.row("IBM");

        //row+column对应的value
        System.out.println(employeeTable.get("IBM","101"));

        System.out.println("List of IBM Employees");
        for (Map.Entry entry : ibmEmployees.entrySet()) {
            System.out.println("Emp Id: " + entry.getKey() + ", Name: " + entry.getValue());
        }

        //table中所有的不重复的key
        Set employers = employeeTable.rowKeySet();
        System.out.print("Employers: ");
        for (String employer : employers) {
            System.out.print(employer + " ");
        }
        System.out.println();

        //得到员工编号为102的所有公司和姓名
        Map EmployerMap = employeeTable.column("102");
        for (Map.Entry entry : EmployerMap.entrySet()) {
            System.out.println("Employer: " + entry.getKey() + ", Name: " + entry.getValue());
        }
    }
}

结果：

[(IBM,101)=Mahesh, (IBM,102)=Ramesh, (IBM,103)=Suresh, (Microsoft,111)=Sohan, (Microsoft,112)=Mohan, (Microsoft,113)=Rohan, (TCS,121)=Ram, (TCS,102)=Shyam, (TCS,123)=Sunil]
[IBM, Microsoft, TCS]
[101, 102, 103, 111, 112, 113, 121, 123]
[Mahesh, Ramesh, Suresh, Sohan, Mohan, Rohan, Ram, Shyam, Sunil]
{IBM={101=Mahesh, 102=Ramesh, 103=Suresh}, Microsoft={111=Sohan, 112=Mohan, 113=Rohan}, TCS={121=Ram, 102=Shyam, 123=Sunil}}
{101={IBM=Mahesh}, 102={IBM=Ramesh, TCS=Shyam}, 103={IBM=Suresh}, 111={Microsoft=Sohan}, 112={Microsoft=Mohan}, 113={Microsoft=Rohan}, 121={TCS=Ram}, 123={TCS=Sunil}}
Mahesh
List of IBM Employees
Emp Id: 101, Name: Mahesh
Emp Id: 102, Name: Ramesh
Emp Id: 103, Name: Suresh
Employers: IBM Microsoft TCS 
Employer: IBM, Name: Ramesh
Employer: TCS, Name: Shyam