Can somebody suggest an easy way to get a reference to a file as a String/InputStream/File/etc type object in a junit test class? Obviously I could paste the file (xml in this case) in as a giant String or read it in as a file but is there a shortcut specific to Junit like this?
public class MyTestClass{
@Resource(path="something.xml")
File myTestFile;
@Test
public void toSomeTest(){
...
}
}
You can try @Rule
annotation. Here is the example from the docs:
public static class UsesExternalResource {
Server myServer = new Server();
@Rule public ExternalResource resource = new ExternalResource() {
@Override
protected void before() throws Throwable {
myServer.connect();
};
@Override
protected void after() {
myServer.disconnect();
};
};
@Test public void testFoo() {
new Client().run(myServer);
}
}
You just need to create FileResource
class extending ExternalResource
.
Full Example
import static org.junit.Assert.*;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExternalResource;
public class TestSomething
{
@Rule
public ResourceFile res = new ResourceFile("/res.txt");
@Test
public void test() throws Exception
{
assertTrue(res.getContent().length() > 0);
assertTrue(res.getFile().exists());
}
}
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import org.junit.rules.ExternalResource;
public class ResourceFile extends ExternalResource
{
String res;
File file = null;
InputStream stream;
public ResourceFile(String res)
{
this.res = res;
}
public File getFile() throws IOException
{
if (file == null)
{
createFile();
}
return file;
}
public InputStream getInputStream()
{
return stream;
}
public InputStream createInputStream()
{
return getClass().getResourceAsStream(res);
}
public String getContent() throws IOException
{
return getContent("utf-8");
}
public String getContent(String charSet) throws IOException
{
InputStreamReader reader = new InputStreamReader(createInputStream(),
Charset.forName(charSet));
char[] tmp = new char[4096];
StringBuilder b = new StringBuilder();
try
{
while (true)
{
int len = reader.read(tmp);
if (len < 0)
{
break;
}
b.append(tmp, 0, len);
}
reader.close();
}
finally
{
reader.close();
}
return b.toString();
}
@Override
protected void before() throws Throwable
{
super.before();
stream = getClass().getResourceAsStream(res);
}
@Override
protected void after()
{
try
{
stream.close();
}
catch (IOException e)
{
// ignore
}
if (file != null)
{
file.delete();
}
super.after();
}
private void createFile() throws IOException
{
file = new File(".",res);
InputStream stream = getClass().getResourceAsStream(res);
try
{
file.createNewFile();
FileOutputStream ostream = null;
try
{
ostream = new FileOutputStream(file);
byte[] buffer = new byte[4096];
while (true)
{
int len = stream.read(buffer);
if (len < 0)
{
break;
}
ostream.write(buffer, 0, len);
}
}
finally
{
if (ostream != null)
{
ostream.close();
}
}
}
finally
{
stream.close();
}
}
}