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How to import correct package for StdDraw?

I want to use the StdDraw package, and I've tried many different ways of importing it.
Of course I tried:
import StdDraw;
But, when I look at the documentation from Princeton here, it shows that StdDraw is part of Objects, so I try this:
import java.lang.Object.StdDraw;
However, this results in an error:
error: cannot find symbol in
import java.lang.Object.StdDraw;
I saw this question here but it does not answer this question either.
How do I import StdDraw? thank you.

if you want to use StdDraw you must have
either the sources
or the classes (best zipped up as jar)
as preferred way you use the sources (see http://introcs.cs.princeton.edu/java/15inout/). it says there "To use these libraries, download StdIn.java, StdOut.java, StdDraw.java, and StdAudio.java into the same directory as your program. "
once you did this the imports should be working.
NOTE: all four files are not in packages, so you should 'download' them into the 'standard' package. That means you have to download them to the root package of your project.
by the way: don't import import java.lang.Object.StdDraw; but do just import import StdDraw;

First of all check encoding of your IDE. It should be set to UTF-8. It is important if you are using MS Windows operating system.
Then create StdDraw.java class in the same package as the package of your program you are writing. Remove class declaration, leave only package declaration.
Then visit this page: https://introcs.cs.princeton.edu/java/stdlib/StdDraw.java .
Copy all its contents (Ctr-A, Ctrl-C) and then paste it into StdDraw.java file you created previously.
StdDraw.java has its own main method so try to run it in order to check that the library works correctly. You should see a window with four strange figures :) .
Don't touch StdDraw.java anymore. Now you can easily import StdDraw library and refer to its methods with name of the class.
Enjoy

Eclipse type / import error with built java file

I have a project where we use a ant buildfile to create some .java files. Those built files need to reference to already existing other java files.
My problem is that the built file can have a code line as for example
arg = (Expr) new Ast.BinaryOP(lhs, BOp.B_MINUS, rhs);
where it will show an error "Ast.BinaryOP cannot be resolved to a type". I then can type Ast.BinaryOP again and use autocomplete to pick the BinaryOP part and the error will disappear. The same with BOp.B_MINUS.
I did import (probably way too many times) the necessary other files as far as I can tell.
I.e.
import cd.ir.Ast;
import cd.ir.Ast.*;
import cd.ir.Ast.Expr;
import cd.ir.Ast.BinaryOp;
import cd.ir.Ast.BinaryOp.BOp;
So far I tried
restarting Eclipse
'clean' the project
to just run the project anyway (doesn't work)
remove the "Ast." part which will work once again if I do it in Eclipse but not if generated that way
Google the problem, respectively search it on Stackoverflow which turned out to be hard as there are many related issues. There are no good keywords as far as I can tell.
deleted the project from Eclipse and imported it newly
I need to repeatedly run the ant build file to test the code from where the .java file is generated, thus changing all errors manually is not an option.
Thanks for any advice/help in advance. I will gladly provide more information if you tell me what could help.

Hit F5 on the project, open the file, and then try hitting Ctrl+Shift+O to automatically organize the imports.

After consulting with a friend who didn't see the issue either I finally found it. So logical in retrospect but small enough that I spend 2,5h trying to find it:
import cd.ir.Ast.BinaryOp;
vs:
new Ast.BinaryOP(....
BinaryOp vs. BinaryOP

Again, R.java not found

I have a lot of java files in my project so I decided to create packages and organize those files. After putting them in seperate packages like
com.myproject.android.activity
com.myproject.android.adapter
etc...
eclipse wants me to import the R file. From different SO questions I know "Never import the R file". However without that eclipse shows error messages that R.java is missing and wants to import it.
I already did a eclipse restart, clean, and android->fix with no success. My resource files are without errors. Is it safe to import the R file. Any suggestions?

Yes, you can import R files, they are sometimes needed to be imported, e.g. when you define them in a library and you need to use them in the package that uses that library.
You can also use full names - this may make the code more clear even if longer.

Import custom java file

I'm currently trying to read some source code in Java I found online to study and learn the material. I want to compile the files first to make sure they work before I study it. When I try to compile though, the compiler complains that it can't find some of the files it needs to import. So opening up the main.java, I find
package br.com.seimos.minijava;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.ArrayList;
import br.com.seimos.minijava.parser.MiniJavaParser;
import br.com.seimos.minijava.syntaxtree.Program;
import br.com.seimos.minijava.visitor.TreeDumper;
import br.com.seimos.minijava.visitor.TreeFormatter;
The errors I'm getting are coming from not being able to find MiniJavaParser, TreeDumper...the 3rd chunk of code. Those files exist in the same directory as the main file though, so what is going on? What is br.com.seimos.minijava stuff? I tried putting the files in that those folders (as in br\com\seimos\minijava\PUT_FILES_HERE) but still no good. Does br need to be in the root directory?
Thanks, I realize this is probably a really elementary question...

The required directory structure is br/com/seimos/minijava/OTHER_FOLDERS/SOURCE_FILES.java. For instance, the path to MiniJavaParser should be br/com/seimos/minijava/parser/MiniJavaParser.java. You should then run the Java compiler from the parent directory of br.
If you're using Eclipse or another IDE, you should configure your project settings to handle this.

For import br.com.seimos.minijava.parser.MiniJavaParser; your MiniJavaParser class must be in the directory br\com\seimos\minijava\parser\ and not br\com\seimos\minijava\. Similarly for other classes. Try changing it.

You're on the right track. You will need to put those files in br/com/seimos/minijava/... as indicated by the package name of each. Java requires that you put files in a directory hierarchy that matches their package names.
Then, you'll want to compile using a command like:
javac br/com/seimos/minijava/parser/MiniJavaParser.java
This is all a bit inconvenient from the command line, especially for a larger project, so you might be better of getting a Java IDE and having it help you arrange the files.

Importing external java files to Eclipse

I am following this question:
How to get rss feeds android?
And I'm using the code from Mathias Lin.
Notice that in the top, it says:
import org.developerworks.android.FeedParser;
import org.developerworks.android.FeedParserFactory;
import org.developerworks.android.Message;
import org.developerworks.android.ParserType;
import org.xmlpull.v1.XmlSerializer;
I managed to find out how to import an external .jar file (the xmlpull one). Now we have the 4 remaining lines, from org.developerworks.android. I managed to find these 4 files online here: https://www.assembla.com/code/churchmobile/subversion/nodes/FeedParser/trunk/src/org/developerworks/android?rev=25 (I don't know if this is the correct way of doing it).
Now I need my Eclipse project to import these external .java files - how do I do this? Now I have red lines underneath these 4 lines because Eclipse can't find them, obviously.

If you right click on the project in the Navigation window in Eclipse there is an 'Import' option. From there it will open a wizard style series of windows that lets you choose what to import and where to import it from. You can also import at different levels of the project (e.g. in the src folder or into a specific package you have created).