1 package tests.support; 2 3 import java.io.IOException; 4 import java.io.Reader; 5 6 /** 7 * An implementation of {@code Reader} that should serve as the 8 * underlying writer for classes to be tested. 9 * In particular this implementation allows to have IOExecptions thrown on demand. 10 * For simplicity of use and understanding all fields are public. 11 */ 12 public class Support_ASimpleReader extends Reader { 13 14 public static final int DEFAULT_BUFFER_SIZE = 32; 15 16 public char[] buf; 17 18 public int pos; 19 20 public int len; 21 22 // Set to true when exception is wanted: 23 public boolean throwExceptionOnNextUse = false; 24 Support_ASimpleReader()25 public Support_ASimpleReader() { 26 this("BEGIN Bla bla, some text...END"); 27 } 28 Support_ASimpleReader(boolean throwException)29 public Support_ASimpleReader(boolean throwException) { 30 this(); 31 throwExceptionOnNextUse = throwException; 32 } 33 Support_ASimpleReader(String input)34 public Support_ASimpleReader(String input) { 35 buf = input.toCharArray(); 36 pos = 0; 37 len = buf.length; 38 } 39 40 @Override close()41 public void close() throws IOException { 42 if (throwExceptionOnNextUse) { 43 throw new IOException("Exception thrown for testing purpose."); 44 } 45 } 46 47 @Override ready()48 public boolean ready() throws IOException { 49 if (throwExceptionOnNextUse) { 50 throw new IOException("Exception thrown for testing purpose."); 51 } 52 return len > pos; 53 } 54 55 @Override read(char[] dest, int offset, int count)56 public int read(char[] dest, int offset, int count) throws IOException { 57 if (throwExceptionOnNextUse) { 58 throw new IOException("Exception thrown for testing purpose."); 59 } 60 int available = len - pos; 61 if (available > 0) { 62 int readable = (available < count ? available : count); 63 System.arraycopy(buf, pos, dest, offset, readable); 64 pos += readable; 65 return readable; 66 } else { 67 return -1; 68 } 69 } 70 } 71