|The methods of which class?|
I assume you mean String.
Then have a look at std::string. It is a large class and has many similar methods, so you'll need to spend some time reading through all the documentation. You possibly won't find exact equivalents to the Java methods but you'll still be able to do what you need.
Sorry I misread your post and thought you were asking about C++. In C, have a look at strchr, strrchr, and strstr.