SCA初探

SCA其实有点象SPRING，只不过sca注入的是一个个实在的服务而已，快要成为工业标准了。下面笔记DEMO中的一个典型计算器

加法的接口：

package calculator;
/**
  * The Add service interface
  */
 public interface AddService {    double add(double n1, double n2);
}

加法的实现：

package calculator;
/**
  * An implementation of the Add service
  */
 public class AddServiceImpl implements AddService {    public double add(double n1, double n2) {
         return n1 + n2;
     }}

减法的接口：

package calculator;
/**
  * The interface for the multiply service
  */
 public interface SubtractService {    double subtract(double n1, double n2);
}

减法的实现：

package calculator;
/**
  * An implementation of the subtract service.
  */
 public class SubtractServiceImpl implements SubtractService {    public double subtract(double n1, double n2) {
         return n1 - n2;
     }}

乘法的接口：

package calculator;
/**
  * The interface for the multiply service
  */
 public interface MultiplyService {    double multiply(double n1, double n2);
}

乘法的实现：

package calculator;
/**
  * An implementation of the Multiply service.
  */
 public class MultiplyServiceImpl implements MultiplyService {    public double multiply(double n1, double n2) {
         return n1 * n2;
     }}

除法的接口：

package calculator;
/**
  * The divide service interface
  */
 public interface DivideService {    double divide(double n1, double n2);
}

除法的实现：

package calculator;
/**
  * An implementation of the Divide service.
  */
 public class DivideServiceImpl implements DivideService {    public double divide(double n1, double n2) {
         return n1 / n2;
     } }

计算器的接口

package calculator;
 /**
  * The Calculator service interface.
  */
 public interface CalculatorService {    double add(double n1, double n2);
    double subtract(double n1, double n2);
    double multiply(double n1, double n2);
    double divide(double n1, double n2);
}

计算器的实现

package calculator;
import org.osoa.sca.annotations.Reference;
 /**
  * An implementation of the Calculator service.
  */
 public class CalculatorServiceImpl implements CalculatorService {    private AddService addService;
     private SubtractService subtractService;
     private MultiplyService multiplyService;
     private DivideService divideService;    @Reference
     public void setAddService(AddService addService) {
         this.addService = addService;
     }    @Reference
     public void setSubtractService(SubtractService subtractService) {
         this.subtractService = subtractService;
     }    @Reference
     public void setDivideService(DivideService divideService) {
         this.divideService = divideService;
     }    @Reference
     public void setMultiplyService(MultiplyService multiplyService) {
         this.multiplyService = multiplyService;
     }    public double add(double n1, double n2) {
         return addService.add(n1, n2);
     }    public double subtract(double n1, double n2) {
         return subtractService.subtract(n1, n2);
     }    public double multiply(double n1, double n2) {
         return multiplyService.multiply(n1, n2);
     }    public double divide(double n1, double n2) {
         return divideService.divide(n1, n2);
     }}

calculator.composite组装文件

<composite xmlns="http://www.osoa.org/xmlns/sca/1.0"
            targetNamespace="http://sample"
            xmlns:sample="http://sample"
            name="Calculator">    <component name="CalculatorServiceComponent">
   <implementation.java class="calculator.CalculatorServiceImpl"/>
         <reference name="addService" target="AddServiceComponent" />
         <reference name="subtractService" target="SubtractServiceComponent" />
         <reference name="multiplyService" target="MultiplyServiceComponent" />
         <reference name="divideService" target="DivideServiceComponent" />
     </component>    <component name="AddServiceComponent">
         <implementation.java class="calculator.AddServiceImpl"/>
     </component>    <component name="SubtractServiceComponent">
         <implementation.java class="calculator.SubtractServiceImpl"/>
     </component>    <component name="MultiplyServiceComponent">
         <implementation.java class="calculator.MultiplyServiceImpl"/>
     </component>    <component name="DivideServiceComponent">
         <implementation.java class="calculator.DivideServiceImpl"/>
     </component></composite>

客户端使用

package calculator;
import org.apache.tuscany.sca.host.embedded.SCADomain;
/**
  * This client program shows how to create an SCA runtime, start it,
  * and locate and invoke a SCA component
  */
 public class CalculatorClient {
     public static void main(String[] args) throws Exception {        SCADomain scaDomain = SCADomain.newInstance("Calculator.composite");
         
         CalculatorService calculatorService = 
             scaDomain.getService(CalculatorService.class, "CalculatorServiceComponent");        // Calculate
         System.out.println("3 + 2=" + calculatorService.add(3, 2));
         System.out.println("3 - 2=" + calculatorService.subtract(3, 2));
         System.out.println("3 * 2=" + calculatorService.multiply(3, 2));
         System.out.println("3 / 2=" + calculatorService.divide(3, 2));        scaDomain.close();
     }}