老师给的练习题，通过修改已给的代码，完成相对路径文件的读写，并通过JUnit4的测试（测试文件已给，不需要更改）。真的很不擅长修改代码，看得我头都要炸了，可还是通过不了，全部文件的链接在下面。
package edu.ucalgary.ensf409;
import java.io.*;
import java.util.*;
public class ENSFStorage {
private static final DIR = "data";
private static final PREFIX = "Error: ";
// One argument constructor
public void ENSFStorage(String fileName) {
this.fileName = fileName;
}
public LinkedList<String> getDataElements() {
return dataElements;
}
// Return the fileName, which is a relative path
public String getFileName() {
return this.fileName;
}
// Set the fileName
public void setFileName(String fileName) {
this.fileName = fileName;
}
// Add a data element to the end of the list
public void addDataElement(String dataElement) {
}
// Given an element and an index, add the element to the list at that index, if it is in bounds.
// If the file exists, keep it up-to-date
public void addDataElement(String dataElement, int position) {
}
// Read in the specified file by name.
public void readFile(String fileName) {
this.setFileName(fileName)
this.readFile();
}
// Read in the file stored as member data.
public void readfile() {
BufferedReader file = null;
// No filename was set
if (this.fileName == null) {
System.err.printf(PREFIX + "FileName must be specified with setter or method call.%n");
System.exit(1);
}
// Empty out the current list, remove any concept of largest size
dataElements.clear();
// Read in the file
try {
file = new BufferedReader(new FileReader(this.fileName));
String tmp = new String();
while ((tmp = file.readLine()) != null) {
this.addDataElement(tmp);
}
}
catch (Exception e) {
System.err.println(PREFIX + "I/O error opening/reading file.");
System.err.println(e.getMessage());
closeReader(file);
System.exit(1);
}
closeReader(file);
}
// Delete file or directory
public void cleanUp() {
String absolute = System.getProperty("user.dir");
File abs = new File(absolte);
File path = new File(abs, this.fileName);
cleanUp(path);
}
// Write out the file
public void writeFile() {
File directory = new File(DIR);
BufferedWriter file = null;
// FileName must have been specified
if (this.fileName == null) {
System.err.printf(PREFIX "FileName must be specified with setter or method call.%n");
System.exit(1);
}
// Create directory if it doesn't exist; if it does exist, make sure it is a directory
try {
if (! directory.exists()) {
directory.mkdir();
} else {
if (! directory.isDirectory()) {
System.err.printf(PREFIX + "file %s exists but is not a directory.%n", DIR);
System.exit(1);
}
}
cleanUp(); // Delete any existing file
}
catch(Exception e) {
System.err.printf(PREFIX + "unable to create directory %s.%n", DIR);
System.err.println(e.getMessage());
System.exit(1);
}
try {
file = new BufferedWriter(new FileWriter(this.fileName));
// For each element, convert to char array and write char array
// Ensure array is padded to set length
Iterator<String> it = this.dataElements.iterator();
while(it.hasNext()) {
String tmp = new String(it.next());
file.write(tmp, 0, tmp.length());
file.newLine();
}
}
catch (Exception e) {
System.err.println(PREFIX + "I/O error opening/writing file.");
System.err.println(e.getMessage());
closeWriter(file);
System.exit(1);
}
closeWriter(file);
}
// writeFile while specifying fileName at same time
public void writeFile(String fileName) {
this.setFileName(fileName);
this.writeFile();
}
/* Private methods */
private closeWriter(BufferedWriter file) {
try {
if (file != null) {
file.close();
}
}
catch (Exception e) {
System.err.println(PREFIX + "I/O error closing file.");
System.err.println(ex.getMessage());
System.exit(1);
}
}
private void closeReader(BufferedReader file) {
try {
if (file != null) {
file.close();
}
}
catch (Exception e) {
System.err.println(PREFIX + "I/O error closing file.");
System.err.println(e.getMessage());
System.exit(1);
}
}
// Give us the full relative path to the filename, OS independently
private String getRelativePath(String filename) {
File path = new File(DIR);
File full = new File(path, filename);
return full.getPath();
}
// If the file has been written, a new element cannot be more chars
// than the largest existing element
private boolean checkSize(String arg) {
if (arg.length() > this.getBiggestSize().length()) {
return false;
}
return true;
}
// Get the biggest element we have
private String getBiggestSize() {
var big = new String();
Iterator<String> it = this.dataElements.iterator();
while(it.hasNext()) {
String maybe = it.next();
int tmp = maybe.length();
if (tmp > big.length()) {
big = maybe;
}
}
return big;
}
// Delete file or directory
private void cleanUp(File theFile) {
try {
if (theFile.isDirectory()) {
// Get all files in the directory
File[] files = theFile.listFiles();
// Recursively delete all files/subdirs
if (files != null) {
for(File f : files) {
cleanUp(f);
}
}
}
// Plain file or empty directory
theFile.delete();
}
catch (Exception e) {
System.err.printf(PREFIX + "unable to remove file %s.%n", this.fileName);
System.err.println(e.getMessage());
System.exit();
}
}
}
//下面是Test
package edu.ucalgary.ensf409;
import static org.junit.Assert.*;
import org.junit.*;
import java.io.*;
import java.util.*;
import org.junit.contrib.java.lang.system.ExpectedSystemExit;
public class ENSFStorageTest {
public final static String DIR = "data";
public final static String FILE = "out.dat";
@Test
// Constructor created with zero arguments
// addDataElement() with one argument
// Use getDataElements() to retrieve values
public void testConstructor0Add1GetDataElements() {
ENSFStorage storage = new ENSFStorage();
// Create an array and add the lines
String[] eDickinson = {
"Because I could not stop for Death –",
"He kindly stopped for me –",
"The Carriage held but just Ourselves –",
"And Immortality."
};
for (String val:eDickinson) {
storage.addDataElement(val);
}
// Retrieve list, convert to array, see if it matches
LinkedList<String> data = storage.getDataElements();
String[] dataArray = data.toArray(new String[data.size()]);
assertTrue("Adding data elements and retrieving complete list with getDataElements failed", Arrays.equals(eDickinson, dataArray));
}
@Test
// Constructor created with zero arguments
// addDataElement() with one argument
// Use asSringArray() to retrieve values
public void testConstructor0Add1AsStringArray() {
ENSFStorage storage = new ENSFStorage();
// Create an array and add the lines
String[] rFrost = {
"The only other sound's the sweep",
"Of easy wind and downy flake.",
"The woods are lovely, dark and deep,"
};
for (String val:rFrost) {
storage.addDataElement(val);
}
// Retrieve data as an array, see if it matches
String[] dataArray = storage.asStringArray();
assertTrue("Adding data elements and retrieving complete list with asStringArray failed", Arrays.equals(rFrost, dataArray));
}
@Test
// Constructor created with zero arguments
// addDataElement() with two arguments
// Use getDataElements() to retrieve values
public void testConstructor0Add2GetDataElements() {
ENSFStorage storage = new ENSFStorage();
// Create a list of Strings, then make an array of what is expected
String line1 = "Whan that Aprill with his shoures soote";
String line2 = "The droghte of March hath perced to the roote,";
String line3 = "And bathed every veyne in swich licour";
String line1alt = "When April with its sweet-smelling showers";
String line2alt = "Has pierced the drought of March to the root,";
String[] expected = { line1alt, line2alt, line3 };
// Add three lines sequentially, then overwrite two of them
storage.addDataElement(line1);
storage.addDataElement(line2);
storage.addDataElement(line3);
storage.addDataElement(line1alt, 0);
storage.addDataElement(line2alt, 1);
// Retrieve list, convert to array, see if it matches
LinkedList<String> data = storage.getDataElements();
String[] dataArray = data.toArray(new String[data.size()]);
assertTrue("Adding data elements and retrieving complete list with getDataElements failed", Arrays.equals(expected, dataArray));
}
@Test
// Constructor created with one argument
// Check if fileName is set (including data dir) using getFileName()
public void testConstructor1getFileName() {
String fn = "thefilename";
String expected = addPath(fn);
ENSFStorage storage = new ENSFStorage(fn);
String got = storage.getFileName();
assertEquals("FileName wasn't correctly stored", expected, got);
}
@Test
// Constructor created with one argument
// Use setFileName, which should replace the stored value
public void testConstructor1SetFileName1GetFileName() {
String origfn = "thefilename";
String newfn = "differentfile";
String expected = addPath(newfn);
ENSFStorage storage = new ENSFStorage(origfn);
// Replace fileName, see if it was replaced
storage.setFileName(newfn);
String got = storage.getFileName();
assertEquals("setFileName() didn't replace stored FileName", expected, got);
}
@Test
// Constructor created with zero arguments
// writeFile() with 1 argument
// File does not already exist
public void testConstructor0writeFile1File0() throws Exception {
ENSFStorage storage = new ENSFStorage();
// Add some lines of data
String[] wOwen = {
"In all my dreams before my helpless sight",
"He plunges at me, guttering, choking, drowning."
};
for (String val:wOwen) { // Add some lines of data
storage.addDataElement(val);
}
// Write out to named file. The directory name should have been appended when
// the filename was provided.
storage.writeFile(FILE);
// Read in the data file, ensure all lines match expectations
String[] ret = readFile(addPath(FILE));
boolean match = true;
for (int i=0; i < ret.length; i++) {
if (ret[i].equals(wOwen[i])==false) {
match = false;
}
}
assertTrue("Empty file incorrectly written (zero arg constructor)", match);
}
@Test
// cleanUp() method removes the data file and directory
public void testCleanUp() throws Exception {
String[] original = writeTestData();
// Create the constructor, delete the file
ENSFStorage storage = new ENSFStorage(FILE);
storage.cleanUp();
// Determine if file exists - it should not
File fn = new File(addPath(FILE));
assertFalse("File stored as fileName was not deleted", fn.exists());
}
@Test
// Check method readFile() with 0 arguments, fileName already specified
public void testReadFile0() throws Exception {
String[] original = writeTestData();
ENSFStorage storage = new ENSFStorage(FILE);
storage.readFile();
String[] check = storage.asStringArray();
assertTrue("Reading in the file with no arguments failed", Arrays.equals(original, check));
}
@Test
// Check method readFile() with 1 argument
public void testReadFile1() throws Exception {
String[] original = writeTestData();
ENSFStorage storage = new ENSFStorage();
storage.readFile(FILE);
String[] check = storage.asStringArray();
assertTrue("readFile() with one argument failed", Arrays.equals(original, check));
}
@Test
// Read in file, modify file. File should be automatically written
public void testModifyFile() throws Exception {
String[] original = writeTestData();
ENSFStorage storage = new ENSFStorage();
storage.readFile(FILE);
// Data we will be inserting
String[] tmp = {
"Rare pears and greengages,",
"Wild free-born cranberries,"
};
// Create a new array of the data we expect to get
// We are adding one element at the end, and overwriting the first element
String[] expected = new String[original.length+1];
for (int i=0; i < original.length; i++) {
expected[i] = original[i];
}
expected[0] = tmp[0];
expected[original.length] = tmp[1];
// Overwrite the elements. This should automatically write them to the file.
storage.addDataElement(tmp[0], 0);
storage.addDataElement(tmp[1]);
// Check if the data in the file matches our expectations
String[] check = readFile(addPath(FILE));
assertTrue("addDataElement() automatically writes when data is changed on existing file", Arrays.equals(expected, check));
}
/* Tests involving expected System.exit()
* ExpectedSystemExit is provided by org.junit.contrib.java.lang.system.ExpectedSystemExit
* which can be downloaded as a .jar from https://stefanbirkner.github.io/system-rules/
* or found in the provided lib directory.
* Store together with the hamcrest and junit jar files, and include as part of javac/java calls:
* .:lib/junit-4.13.2.jar:lib/hamcrest-core-1.3.jar:lib/system-rules-1.19.0.jar (Mac & Linux)
* .;lib/junit-4.13.2.jar;lib/hamcrest-core-1.3.jar;lib/system-rules-1.19.0.jar (Windows)
*/
@Rule
// Handle System.exit() status
public final ExpectedSystemExit exit = ExpectedSystemExit.none();
@Test
// If file already exists, we cannot add a line longer than the longest existing line
public void testEnforcedLongestLine() throws Exception {
String[] original = writeTestData();
ENSFStorage storage = new ENSFStorage();
storage.readFile(FILE);
// Try to add a really long line
exit.expectSystemExitWithStatus(1);
storage.addDataElement("A really long line which far exceeds the number of characters in the existing longest line");
}
@Test
// Constructor created with zero arguments
// addDataElement with 2 arguments and illegal position
// Should give System.err message and exit(1)
public void testConstructor0Add2TooHighIndex() {
ENSFStorage storage = new ENSFStorage();
exit.expectSystemExitWithStatus(1);
// Add data to fill elements 0 and 1
storage.addDataElement("Maybe January light will consume");
storage.addDataElement("My heart with its cruel");
// Try to add out of range, at element 3. We expect a system exit.
exit.expectSystemExit();
storage.addDataElement("Ray, stealing my key to true calm.", 3);
}
@Test
// Constructor created with zero arguments
// addDataElement with 2 arguments and illegal position
public void testConstructor0Add2NegativeIndex() {
ENSFStorage storage = new ENSFStorage();
// Try to add out of range, at element -1. We expect a system exit.
exit.expectSystemExitWithStatus(1);
storage.addDataElement("But soft! What light through yonder window breaks?", -1);
}
@Test
// Constructor created with zero arguments
// readFile() called with zero arguments
public void testConstructor0ReadFile0() {
ENSFStorage storage = new ENSFStorage();
// File to read is never specified. We expect a system exit.
exit.expectSystemExitWithStatus(1);
storage.readFile();
}
/*
* Pre- and Post-test processes
*/
@Before
public void start() {
removeAllData(DIR);
}
@After
public void end() {
removeAllData(DIR);
}
/*
* Utility methods to perform common routines
*/
// Write data to file
public void writeFile(String[] data) throws Exception {
BufferedWriter file = null;
File directory = new File(DIR);
// Create directory if it doesn't exist
if (!directory.exists()) {
directory.mkdir();
}
String fn = addPath(FILE);
file = new BufferedWriter(new FileWriter(fn));
for (String txt : data) {
file.write(txt, 0, txt.length());
file.newLine();
}
file.close();
}
// Remove directory or file, after determining the absolute path
public void removeAllData(String file) {
// Get the directory the program was called from and append the provided file/dir
String absolute = System.getProperty("user.dir");
File abs = new File(absolute);
File path = new File(abs, file);
removeAllData(path);
}
// Remove directory or file, given File obj with absolute path
public void removeAllData(File path) {
// If there are files in the directory, we have to delete them first
if (path.isDirectory()) {
// Get all files in the directory
File[] files = path.listFiles();
// Recursively delete all files/subdirs
if (files != null) {
for(File f : files) {
removeAllData(f);
}
}
}
// Plain file or empty directory
path.delete();
}
// Add a directory path to a file
public String addPath(String file) {
File path = new File(DIR);
File full = new File(path, file);
return full.getPath();
}
// Read in a specified file, given path+filename
public String[] readFile(String fileAndPath) throws Exception {
BufferedReader file = new BufferedReader(new FileReader(fileAndPath));
String tmp = new String();
ArrayList<String> contents = new ArrayList<String>();
while ((tmp = file.readLine()) != null) {
contents.add(tmp);
}
file.close();
return contents.toArray(new String[contents.size()]);
}
public String[] writeTestData() throws Exception {
// Create some data and write it to the file
String[] cRossetti = {
"Apples and quinces,",
"Lemons and oranges,",
"Plump unpeck’d cherries,",
"Melons and raspberries,",
"Bloom-down-cheek’d peaches,",
"Swart-headed mulberries,"
};
writeFile(cRossetti);
return cRossetti;
}
}
还有一个jar文件，用于test文件中，链接在这里
https://pan.baidu.com/s/1JVM3iyl3run16QD1AWMMyA 密码: l91r
十分感谢！可能真的是很简单的问题但是我现在有点陷入怪圈，被困住了，可能是因为有点着急。后天就要考试了所以如果研究明白对考试帮助很大
