Example

public class ClassA {
int i;
int j;
int k;
int h;
public void methodA() {
if(i<j & k==h) {
// ...
}
}

}
Solution
Change the & to &&

public class ClassA {
int i;
int j;
int k;
int h;
public void methodA() {
if(i<j && k==h) {
// ...
}
}

}