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层次风格
层次风格
了解很多其它软件体系结构风格
层次系统
–在层次系统中，系统被组织成若干个层次。每一个层次由一系列组件组成
–下层组件向上层组件提供服务
–上层组件被看作是下层组件的客户
§系统中的每一层都要承担两个角色。
–首先，它要为结构中的上层提供服务；
–其次。它要作为结构中以下层次的客户，调用下层提供的功能函数。
–最高层和最低层例外。
基本组件：各层次内部包括的组件
§连接件：层间的交互协议
§拓扑结构：分层
§拓扑约束：对相邻层间交互的约束
–集中式部署(Mainframe)
–分布式部署(Distributed)
长处：
–支持基于抽象程度递增的系统设计，有利于设计者对一个复杂
系统进行分解。
–局部依赖性，由于每一层至多和相邻的上下层交互。因此功能
的改变通常影响相邻的上下层；
–可复用性，假设某独立层保证了功能的完整性而且提供了文档
化的接口。便可在多个语境中复用。
–可替换性，仅仅要提供的服务接口定义不变，同一层的不同实现
能够交换使用。这样，就能够定义一组标准的接口，而同意各
种不同的实现方法。
–对标准化的支持。清晰定义而且广泛接受的抽象层次可以促进
实现标准化的任务和接口开发，相同接口的不同实现可以互换
使用。
–可測试性。具有定义明白的层接口以及交换层接口的各个实现
的能力提高了可測试性。
缺点：
并非每一个系统都能够非常easy地划分为分层的模式。甚至即使一个系统的逻辑结构是层次化的。出于对系统性能的考虑。系统设计师不得不把一些低级或高级的功能综合起来；
§效率的减少：
–由分层风格构成的系统，执行效率往往低于总体结构。
–在上层中的服务假设有非常多依赖于最底层，则相关的数据必须通过一些中间层的若干次转化，才干传到；
§非常难找到合适的、正确的层次抽象方法：
–层数太少，分层不能全然发挥这样的风格的可复用性、可更改性和可移植性上的潜力。
–层数过多。则引入不必要的复杂性和层间隔离冗余以及层间传输开销。
–眼下，没有可行的广为人们所认可的层粒度的确定和层任务的分配方法。
程序：
第一层为用户图形界面层
importjava.awt.*;
importjava.util.*;
importjavax.swing.*;
importjava.awt.event.*;
importcom.sun.java.swing.plaf.windows.*;
public class TestingGUI extendsJPanel{
private JTextArea txtTestInfo, txtTestcase;
private JLabel lblTestcases;
private JPanel buttonPanel;
private JComboBox cmbTestcases;
private static final String CASE_BUBBLE= "TC1-Test BubbleSort";
private static final String CASE_HEAP= "TC2-Test Heap Sort";
private static final String CASE_INSERTION= "TC3-Test InsertionSort";
private static final String EXECUTE = "Execute";
private static final String EXIT = "Exit";
public TestingGUI(){
txtTestInfo=new JTextArea("Test outputfrom source shown here\n", 6, 20);
txtTestInfo.setLineWrap(true);
txtTestcase = new JTextArea("Testcaseinfo and test validation shown here\n", 4, 15);
txtTestcase.setLineWrap(true);
buildUpScrollGUI();
}
private void buildUpScrollGUI(){
setUpButtonPanel();
JScrollPane btnPane = new JScrollPane(buttonPanel);
JScrollPane textPane = newJScrollPane(txtTestcase);
textPane.setMinimumSize(new Dimension(250,150));
JScrollPane testDataPane = newJScrollPane(txtTestInfo);
JSplitPane upSplitPane = newJSplitPane(JSplitPane.HORIZONTAL_SPLIT);
upSplitPane.setLeftComponent(btnPane);
upSplitPane.setRightComponent(testDataPane);
JScrollPane downPane = newJScrollPane(textPane);
Dimension minimumSize = new Dimension(130,100);
btnPane.setMinimumSize(minimumSize);
textPane.setMinimumSize(new Dimension(100,100));
upSplitPane.setDividerLocation(270);
upSplitPane.setPreferredSize(newDimension(500, 300));
JSplitPane bigSplitPane = newJSplitPane(JSplitPane.VERTICAL_SPLIT, upSplitPane, downPane);
bigSplitPane.setDividerLocation(190);
add(bigSplitPane);
setSize(new Dimension(500, 400));
setVisible(true);
}
private void setUpButtonPanel(){
lblTestcases = new JLabel("TestCases:");
cmbTestcases = new JComboBox();
cmbTestcases.addItem(CASE_BUBBLE);
cmbTestcases.addItem(CASE_HEAP);
cmbTestcases.addItem(CASE_INSERTION);
//Create the open button
JButton executeBtn = new JButton(EXECUTE);
executeBtn.setMnemonic(KeyEvent.VK_S);
JButton exitButton = new JButton(EXIT);
exitButton.setMnemonic(KeyEvent.VK_X);
BtnListener objButtonHandler = newBtnListener();
// add action Listener
executeBtn.addActionListener(objButtonHandler);
exitButton.addActionListener(objButtonHandler);
buttonPanel = new JPanel();
GridBagLayout gridbag = newGridBagLayout();
buttonPanel.setLayout(gridbag);
GridBagConstraints gbc = newGridBagConstraints();
buttonPanel.add(lblTestcases);
buttonPanel.add(cmbTestcases);
buttonPanel.add(executeBtn);
buttonPanel.add(exitButton);
gbc.insets.top = 5;
gbc.insets.bottom = 5;
gbc.insets.left = 5;
gbc.insets.right = 5;
gbc.anchor = GridBagConstraints.EAST;
gbc.gridx = 0;
gbc.gridy = 0;
gridbag.setConstraints(lblTestcases, gbc);
gbc.anchor = GridBagConstraints.WEST;
gbc.gridx = 1;
gbc.gridy = 0;
gridbag.setConstraints(cmbTestcases, gbc);
gbc.anchor = GridBagConstraints.EAST;
gbc.insets.left = 2;
gbc.insets.right = 2;
gbc.insets.top = 25;
gbc.anchor = GridBagConstraints.EAST;
gbc.gridx = 0;
gbc.gridy = 7;
gridbag.setConstraints(executeBtn, gbc);
gbc.anchor = GridBagConstraints.WEST;
gbc.gridx = 1;
gbc.gridy = 7;
gridbag.setConstraints(exitButton, gbc);
}
public void showTestInfo(int[] str ){
txtTestInfo.setText("");
for(int n=0; n< str.length; n++)
txtTestInfo.append(""+str[n]+" ");
}
public void showErrors(String err){
txtTestcase.append(err+"\n");
}
public String getSelectedTestcase() {
return (String)cmbTestcases.getSelectedItem();
}
class BtnListener implements ActionListener{
private Testcase test;
private String selectedTestcase;
public void actionPerformed(ActionEvent e){
String searchResult = null;
int[] output=null;
if (e.getActionCommand().equals(EXIT)){
System.exit(1);
}
if(e.getActionCommand().equals(EXECUTE)){
selectedTestcase = getSelectedTestcase();
if(selectedTestcase.equals(CASE_BUBBLE))
test = new TestcaseBubble();
else if(selectedTestcase.equals(CASE_HEAP))
test = new TestcaseHeap();
elseif(selectedTestcase.equals(CASE_INSERTION))
test = new TestcaseInsertion();
output = test.execute(3000);
showTestInfo(output);
}
showErrors(selectedTestcase);
boolean result =ResultVerification.isResultCorrect(output );
showErrors("No Error found =" +result);
long timeTaken = test.getTimeTaken();
showErrors("Testing Time takes =" + timeTaken+"\n");
}
} // End of class BtnListener
private static void createAndShowGUI(){
JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("LayeredArchitecture- Software Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
TestingGUI newContentPane = newTestingGUI();
newContentPane.setOpaque(true);
frame.setContentPane(newContentPane);
frame.pack();
frame.setVisible(true);
}
static public void main(String argv[]) {
javax.swing.SwingUtilities.invokeLater(newRunnable() {
public void run() {
createAndShowGUI();
}
});
}
}
public class ResultVerification{
static boolean flag = true;
public static booleanisResultCorrect(int[] arr){
for(int k=0; k<arr.length-1; k++){
if(arr[k] > arr[k+1]){
flag=false;
System.out.println("error "+ k);
//break;
}
}
return flag;
}
}
第二层为測试案例层，包含软件測试project师所编写的測试案例
publicinterface Testcase{
public abstract int[] execute(int len);
public abstract long getTimeTaken();
}
class Context {
SortAlgorithm alg;
// Constructor
public Context(SortAlgorithm alg) {
this.alg = alg;
}
public int[] sortIntArray(int[] a) {
return this.alg.sort(a);
}
}
import java.util.Random;
public class IntegerArrGenerator{
public static int[] generateInput(int len){
int[] input= new int[len];
Random r = new Random();
for(int m=0; m< len; m++){
input[m] = r.nextInt(len);
}
return input;
}
}
import java.util.*;
public class TestcaseBubbleimplements Testcase{
private long startTime;
private long timeTaken=0;
public int[] execute(int len) {
startTime = System.currentTimeMillis();
int[] input =IntegerArrGenerator.generateInput(len);
SortAlgorithm sa = new BubbleSort();
Context context = new Context(sa);
int[] intArray = context.sortIntArray(input);
timeTaken =System.currentTimeMillis() - startTime;
return intArray;
}
public long getTimeTaken(){
return timeTaken;
}
}
import java.util.*;
public class TestcaseHeapimplements Testcase{
//static long time;
private long startTime;
private long timeTaken=0;
public int[] execute(int len){
startTime= System.currentTimeMillis();
int[]input = IntegerArrGenerator.generateInput(len);
SortAlgorithmsa = new HeapSort();
Contextcontext = new Context(sa);
int[]intArray = context.sortIntArray(input);
timeTaken= System.currentTimeMillis()-startTime;
return intArray;
}
public long getTimeTaken(){
return timeTaken;
}
}
import java.util.*;
public class TestcaseInsertionimplements Testcase{
private long startTime;
private long timeTaken=0;
public int[] execute(int len){
startTime = System.currentTimeMillis();
int[] input =IntegerArrGenerator.generateInput(len);
SortAlgorithm sa = new InsertSort();
Context context = new Context(sa);
int[] intArray = context.sortIntArray(input);
timeTaken =System.currentTimeMillis()-startTime;
return intArray;
}
public long getTimeTaken(){
return timeTaken;
}
}
第三层为被測试软件层（排序算法）
public interface SortAlgorithm {
int[] sort(int[] nums);
}
public class BubbleSort implementsSortAlgorithm {
public int[] sort(int[] nums){
for(int i = nums.length; --i >= 0;)
for(int j = 0; j < i; j++){
if(nums[j] > nums[j + 1]){
//exchange nums[j+1] withnums[j]
int T =nums[j];
nums[j] = nums[j + 1];
nums[j + 1] = T;
}
}
return nums;
}
}
public class HeapSort implementsSortAlgorithm{
public int[] sort(int nums[ ]) {
for(int i=nums.length; i>1; i--){
buildBinaryHeapTree(nums, i -1);
swapLeadingNodeWithLastNode(nums, i - 1);
}
return nums;
}
public void buildBinaryHeapTree(intarray[], int arrayBound){
int leftChild, rightChild, biggerChild,temp;
int root = (arrayBound-1)/2;
// Find the bigger child index
for(int i=root; i>=0; i--) {
leftChild = (2*i)+1;
rightChild = (2*i)+2;
if((leftChild <= arrayBound)&& (rightChild <= arrayBound)){
if(array[rightChild] >=array[leftChild])
biggerChild =rightChild;
else
biggerChild = leftChild;
}
else{
if(rightChild >arrayBound)
biggerChild = leftChild;
else
biggerChild = rightChild;
}
//swap the integer contained inthe bigger child index
//with that in the currentparent node
if(array[i] <array[biggerChild]){
temp = array[i];
array[i] =array[biggerChild];
array[biggerChild] = temp;
}
}
return;
}
publicstatic void swapLeadingNodeWithLastNode(int array[], int arrayBound){
int temp;
temp = array[0];
array[0] = array[arrayBound];
array[arrayBound] = temp;
return;
}
}
public class InsertSortimplements SortAlgorithm {
public int[] sort(int[] nums){
for (int i = 1; i < nums.length;i++){
int j = i;
int numToBeInserted = nums[i];
while ((j > 0) &&(nums[j-1] > numToBeInserted) ) {
nums[j] = nums[j-1];
j--;
}
nums[j] = numToBeInserted;
}
return nums;
}
}
层次风格