SamplePojo.java

import javax.persistence.Column;  import javax.persistence.Entity;    @Entity  public class SamplePojo {      @Column(name="User_Id")      private int id;      @Column(name="User_Name")      private String name;      @Column(name="Address")      private String address;      @Column(name="Gender")      private boolean gender;      public int getId() {          return id;      }      public void setId(int id) {          this.id = id;      }      public String getName() {          return name;      }      public void setName(String name) {          this.name = name;      }      public String getAddress() {          return address;      }      public void setAddress(String address) {          this.address = address;      }      public boolean isGender() {          return gender;      }      public void setGender(boolean gender) {          this.gender = gender;      }        @Override      public String toString() {          return  "id: " + id + "\n" +                   "name: " + name + "\n"+                  "address: " + address + "\n" +                  "gender: " + (gender ? "Male" : "Female") + "\n\n";      }  }

ResultSetMapper.java

import java.lang.reflect.Field;  import java.lang.reflect.InvocationTargetException;  import java.sql.ResultSet;  import java.sql.ResultSetMetaData;  import java.sql.SQLException;  import java.util.ArrayList;  import java.util.List;    import javax.persistence.Column;  import javax.persistence.Entity;    import org.apache.commons.beanutils.BeanUtils;    public class ResultSetMapper<T> {      @SuppressWarnings("unchecked")      public List<T> mapRersultSetToObject(ResultSet rs, Class outputClass) {          List<T> outputList = null;          try {              // make sure resultset is not null              if (rs != null) {                  // check if outputClass has 'Entity' annotation                  if (outputClass.isAnnotationPresent(Entity.class)) {                      // get the resultset metadata                      ResultSetMetaData rsmd = rs.getMetaData();                      // get all the attributes of outputClass                      Field[] fields = outputClass.getDeclaredFields();                      while (rs.next()) {                          T bean = (T) outputClass.newInstance();                          for (int _iterator = 0; _iterator < rsmd                                  .getColumnCount(); _iterator++) {                              // getting the SQL column name                              String columnName = rsmd                                      .getColumnName(_iterator + 1);                              // reading the value of the SQL column                              Object columnValue = rs.getObject(_iterator + 1);                              // iterating over outputClass attributes to check if any attribute has 'Column' annotation with matching 'name' value                              for (Field field : fields) {                                  if (field.isAnnotationPresent(Column.class)) {                                      Column column = field                                              .getAnnotation(Column.class);                                      if (column.name().equalsIgnoreCase(                                              columnName)                                              && columnValue != null) {                                          BeanUtils.setProperty(bean, field                                                  .getName(), columnValue);                                          break;                                      }                                  }                              }                          }                          if (outputList == null) {                              outputList = new ArrayList<T>();                          }                          outputList.add(bean);                      }                    } else {                      // throw some error                  }              } else {                  return null;              }          } catch (IllegalAccessException e) {              e.printStackTrace();          } catch (SQLException e) {              e.printStackTrace();          } catch (InstantiationException e) {              e.printStackTrace();          } catch (InvocationTargetException e) {              e.printStackTrace();          }          return outputList;      }  }

使用方法

import java.sql.Connection;  import java.sql.DriverManager;  import java.sql.PreparedStatement;  import java.sql.ResultSet;  import java.sql.SQLException;  import java.util.List;    public class SampleMain {      public static void main(String ...args){        try {          ResultSetMapper<SamplePojo> resultSetMapper = new ResultSetMapper<SamplePojo>();          ResultSet resultSet = null;          // simple JDBC code to run SQL query and populate resultSet - START          Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");          String database = "jdbc:odbc:AkDb";           Connection connection = DriverManager.getConnection( database ,"","");          PreparedStatement statement = connection.prepareStatement("SELECT * FROM UsersSample");          resultSet = statement.executeQuery();          // simple JDBC code to run SQL query and populate resultSet - END          List<SamplePojo> pojoList = resultSetMapper.mapRersultSetToObject(resultSet, SamplePojo.class);          // print out the list retrieved from database          if(pojoList != null){              for(SamplePojo pojo : pojoList){                  System.out.println(pojo);              }          }else{              System.out.println("ResultSet is empty. Please check if database table is empty");          }          connection.close();      } catch (ClassNotFoundException e) {          e.printStackTrace();      } catch (SQLException e) {          e.printStackTrace();      }        }  }