專案結構：

建立表單的註解：（注意與屬性註解的作用域的不同）

package HibernateSimulate;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
 * Created by codessl on 2017/9/5 0005.
 */
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME
 
)
public @interface Table {
    String value();
}

package HibernateSimulate;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
 * Created by codessl on 2017/9/5 0005.
 */
@Target(ElementType.FIELD
 
)
@Retention(RetentionPolicy.RUNTIME)
public @interface Column {
    String value();
}

package HibernateSimulate;
/**
 * Created by codessl on 2017/9/5 0005.
 */
@Table("user")
public class Filter {
    @Column("name")
    String name;
    public String getName() {
        return name;
 
}

    public void setName(String name) {
        this.name = name;
}

    public int getId() {
        return id;
}

    public void setId(int id) {
        this.id = id;
}

    public String getEmail() {
        return email;
}

    public void setEmail(String email) {
        this.email = email;
}

    @Column("id")
    int id;
@Column("email")
    String email;
}

建立測試執行的類：

package HibernateSimulate;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
 * Created by codessl on 2017/9/5 0005.
 */
public class Test {
    public static void main(String[] args) {
        //根據name查詢
Filter filter1 = new Filter();
//根據ID查詢
Filter filter2 = new Filter();
//根據email查詢
Filter filter3 = new Filter();
//設定過濾器的各個屬性
filter1.setName("ruanjianlin");
filter2.setId(66);
filter3.setEmail("[email protected],[email protected]");
//根據相關的屬性查詢
query(filter1);
query(filter2);
query(filter3);
}

    public static void query(Object o) {

        //建立sql語句字串拼接物件
StringBuffer sql = new StringBuffer();
sql.append("select * from ");
//獲取註解且通過反射方式獲得屬性
Class c = o.getClass();
Boolean isExistTable = c.isAnnotationPresent(Table.class);
//如果存在表的名稱的註解
if (isExistTable) {
            Table tb = (Table) c.getAnnotation(Table.class);
sql.append(tb.value() + " ");
sql.append("where 1=1 ");
Field[] fields = c.getDeclaredFields();
            for (Field field : fields) {
                Boolean isExistColumn = field.isAnnotationPresent(Column.class);
                if (isExistColumn) {
                    Object result = null;
Column column = field.getAnnotation(Column.class);
String columnGet = column.value();
//通過反射invoke執行method
String methodName = "get" + columnGet.substring(0, 1).toString().toUpperCase() + columnGet.substring(1, columnGet.length());
                    try {
                        try {
                            Method methodInvoke = c.getMethod(methodName);
result = methodInvoke.invoke(o, null);
} catch (NoSuchMethodException e) {
                            e.printStackTrace();
}
                        if (result == null || result instanceof Integer && (int) result == 0) {
                            continue;
} else if (result instanceof Integer) {
                            sql.append("and " + columnGet + "=");
sql.append(result);
}

                        //如果是郵箱的屬性
else if (result.toString().contains(",")) {
                            sql.append("and " + columnGet + " in(");
String[] email = result.toString().split(",");
/* for (String string:email) {
                               sql.append("'"+string+"',");
                           }*/
for (int i = 0; i < email.length; i++) {
                                if (i != email.length - 1) {
                                    sql.append("'" + email[i] + "',");
} else {
                                    sql.append("'" + email[i] + "')");
}
                            }
                        }

                        //如果是姓名
else {
                            sql.append("and " + columnGet + "=");
                            if (result != null) {
                                sql.append("'" + result + "'");
}

                        }
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
} catch (InvocationTargetException e) {
                        e.printStackTrace();
}

                }

            }

            System.out.println(sql);
}
    }

}

原理概括：通過表的註解獲取實體類（表單）名，然後獲取表單的各個屬性資訊，進而通過屬性資訊與反射呼叫get set等方法，然後進行sql語句的拼接，當然進行sql語句拼接時的細節仍需注意比如where的設定，單引號，型別的處理，and連線符等等，需要自行進行實踐方可體會相關技巧。