tablecreationprocessorfactory.java

随书代码 上面有书中的大部分代码

//: annotations/database/TableCreationProcessorFactory.java
// The database example using Visitor.
// {Exec: apt -factory
// annotations.database.TableCreationProcessorFactory
// database/Member.java -s database}
package annotations.database;
import com.sun.mirror.apt.*;
import com.sun.mirror.declaration.*;
import com.sun.mirror.util.*;
import java.util.*;
import static com.sun.mirror.util.DeclarationVisitors.*;

public class TableCreationProcessorFactory
  implements AnnotationProcessorFactory {
  public AnnotationProcessor getProcessorFor(
    Set<AnnotationTypeDeclaration> atds,
    AnnotationProcessorEnvironment env) {
    return new TableCreationProcessor(env);
  }
  public Collection<String> supportedAnnotationTypes() {
    return Arrays.asList(
      "annotations.database.DBTable",
      "annotations.database.Constraints",
      "annotations.database.SQLString",
      "annotations.database.SQLInteger");
  }
  public Collection<String> supportedOptions() {
    return Collections.emptySet();
  }
  private static class TableCreationProcessor
    implements AnnotationProcessor {
    private final AnnotationProcessorEnvironment env;
    private String sql = "";
    public TableCreationProcessor(
      AnnotationProcessorEnvironment env) {
      this.env = env;
    }
    public void process() {
      for(TypeDeclaration typeDecl :
        env.getSpecifiedTypeDeclarations()) {
        typeDecl.accept(getDeclarationScanner(
          new TableCreationVisitor(), NO_OP));
        sql = sql.substring(0, sql.length() - 1) + ");";
        System.out.println("creation SQL is :\n" + sql);
        sql = "";
      }
    }
    private class TableCreationVisitor
      extends SimpleDeclarationVisitor {
      public void visitClassDeclaration(
        ClassDeclaration d) {
        DBTable dbTable = d.getAnnotation(DBTable.class);
        if(dbTable != null) {
          sql += "CREATE TABLE ";
          sql += (dbTable.name().length() < 1)
            ? d.getSimpleName().toUpperCase()
            : dbTable.name();
          sql += " (";
        }
      }
      public void visitFieldDeclaration(
        FieldDeclaration d) {
        String columnName = "";
        if(d.getAnnotation(SQLInteger.class) != null) {
          SQLInteger sInt = d.getAnnotation(
              SQLInteger.class);
          // Use field name if name not specified
          if(sInt.name().length() < 1)
            columnName = d.getSimpleName().toUpperCase();
          else
            columnName = sInt.name();
          sql += "\n    " + columnName + " INT" +
            getConstraints(sInt.constraints()) + ",";
        }
        if(d.getAnnotation(SQLString.class) != null) {
          SQLString sString = d.getAnnotation(
              SQLString.class);
          // Use field name if name not specified.
          if(sString.name().length() < 1)
            columnName = d.getSimpleName().toUpperCase();
          else
            columnName = sString.name();
          sql += "\n    " + columnName + " VARCHAR(" +
            sString.value() + ")" +
            getConstraints(sString.constraints()) + ",";
        }
      }
      private String getConstraints(Constraints con) {
        String constraints = "";
        if(!con.allowNull())
          constraints += " NOT NULL";
        if(con.primaryKey())
          constraints += " PRIMARY KEY";
        if(con.unique())
          constraints += " UNIQUE";
        return constraints;
      }
    }
  }
} ///:~