java - Use mock object in test method implementation -

i have question. there's method implementation using objects. i'd test method not using objects invoking.

class object1 {      public void method1() {         object2 object2 = new object2();         string info = object2.getinfo();         // ...         // working info, want test         // ...     }  }  class object1test {     @test     public void testmethod1() {         object1 object1 = new object1();         object1.method(); // want run method without invoking object2     } } 

could me understand how in junit while testing method1() can mock using of object2 object2mock?

you need make changes class achieve trying do.

class object1 {     private object2 object2 = new object2();      /* setter method object2 */     public void setobject2(object2 object2) {          this.object2 = object2;     }      public void method1() {         string info = object2.getinfo();         // ...         // working info, want test         // ...     } } 

now have call setter-method mocked object object2.

class object1test {     @test     public void testmethod1() {         object1 object1 = new object1();         object1.setobject2(/* pass mocked object here */);         object1.method(); // want run method without invoking object2     } } 

you can use mockito or jmock create object mocks. can tell mockito return dummy response whenever getinfo() invoked on object2. example,

mockito.when(mockedobject2.getinfo()).thenreturn("dummy response");