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comparison artifact-database/src/main/java/de/intevation/artifactdatabase/ProxyArtifact.java @ 89:d348fe1fd822

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More javadoc (fixes small glitches, too). artifacts/trunk@845 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author Sascha L. Teichmann <sascha.teichmann@intevation.de>
date Fri, 26 Mar 2010 16:16:32 +0000
parents b2e0cb83631c
children 68285f7bc476
comparison
equal deleted inserted replaced
88:69c84cf7c5d7 89:d348fe1fd822
9 9
10 import java.io.IOException; 10 import java.io.IOException;
11 import java.io.OutputStream; 11 import java.io.OutputStream;
12 12
13 /** 13 /**
14 * The proxy artifact is a wrapper around another artifact. It simply forwards
15 * the interface calls to this underlaying artifact.
16 * The reason for using proxy artifacts is enable the workflow to exchange
17 * artifacts at any time by something else without losing the concrete
18 * artifact. From the outside it always looks like there is only one
19 * distinct artifact.<br>
20 *
21 * An inner artifact is able to replace itself by indirectly hand over
22 * the replacement via the call context to the proxy artifact.<br>
23 * To do so the proxied artifact has to call
24 * <code>callContext.getContextValue(EPLACE_PROXY, replacement);</code>.
25 * After the current call (describe, feed, advance and out) of the proxied
26 * artifact is finished the proxy artifact replaces the former proxied artifact
27 * with the replacement.
28 *
14 * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a> 29 * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
15 */ 30 */
16 public class ProxyArtifact 31 public class ProxyArtifact
17 extends DefaultArtifact 32 extends DefaultArtifact
18 { 33 {
34 /**
35 * Key to signal that the proxied artifact should be replaced.
36 */
19 public static final Object REPLACE_PROXY = new Object(); 37 public static final Object REPLACE_PROXY = new Object();
20 38
21 private static Logger logger = Logger.getLogger(ProxyArtifact.class); 39 private static Logger logger = Logger.getLogger(ProxyArtifact.class);
22 40
41 /**
42 * The proxied artifact.
43 */
23 protected Artifact proxied; 44 protected Artifact proxied;
24 45
46 /**
47 * Default constructor.
48 */
25 public ProxyArtifact() { 49 public ProxyArtifact() {
26 } 50 }
27 51
52 /**
53 * Constructor to create a new proxy artifact around a given artifact.
54 * @param proxied The artifact to be proxied.
55 */
28 public ProxyArtifact(Artifact proxied) { 56 public ProxyArtifact(Artifact proxied) {
29 this.proxied = proxied; 57 this.proxied = proxied;
30 } 58 }
31 59
60 /**
61 * The currently proxied artifact.
62 * @return The proxied artifact.
63 */
32 public Artifact getProxied() { 64 public Artifact getProxied() {
33 return proxied; 65 return proxied;
34 } 66 }
35 67
68 /**
69 * Explicitly set the proxied artifacts.
70 * @param proxied
71 */
36 public void setProxied(Artifact proxied) { 72 public void setProxied(Artifact proxied) {
37 this.proxied = proxied; 73 this.proxied = proxied;
38 } 74 }
39 75
76 @Override
40 public void setIdentifier(String identifier) { 77 public void setIdentifier(String identifier) {
41 this.identifier = identifier; 78 this.identifier = identifier;
42 79
43 if (proxied != null) 80 if (proxied != null)
44 proxied.setIdentifier(identifier); 81 proxied.setIdentifier(identifier);
45 } 82 }
46 83
84 /**
85 * Method to check if the current proxied artifact should be replaced
86 * by a new one coming from the call context.
87 * @param callContext
88 */
47 protected void checkReplacement(CallContext callContext) { 89 protected void checkReplacement(CallContext callContext) {
48 Object replacement = callContext.getContextValue(REPLACE_PROXY); 90 Object replacement = callContext.getContextValue(REPLACE_PROXY);
49 if (replacement instanceof Artifact) { 91 if (replacement instanceof Artifact) {
50 setProxied((Artifact)replacement); 92 setProxied((Artifact)replacement);
51 } 93 }
52 } 94 }
53 95
96 @Override
54 public String hash() { 97 public String hash() {
55 return proxied != null 98 return proxied != null
56 ? proxied.hash() 99 ? proxied.hash()
57 : super.hash(); 100 : super.hash();
58 } 101 }
59 102
103 @Override
60 public Document describe(Document data, CallContext context) { 104 public Document describe(Document data, CallContext context) {
61 try { 105 try {
62 return proxied != null 106 return proxied != null
63 ? proxied.describe(data, context) 107 ? proxied.describe(data, context)
64 : super.describe(data, context); 108 : super.describe(data, context);
66 finally { 110 finally {
67 checkReplacement(context); 111 checkReplacement(context);
68 } 112 }
69 } 113 }
70 114
115 @Override
71 public Document advance(Document target, CallContext context) { 116 public Document advance(Document target, CallContext context) {
72 try { 117 try {
73 return proxied != null 118 return proxied != null
74 ? proxied.advance(target, context) 119 ? proxied.advance(target, context)
75 : super.advance(target, context); 120 : super.advance(target, context);
77 finally { 122 finally {
78 checkReplacement(context); 123 checkReplacement(context);
79 } 124 }
80 } 125 }
81 126
127 @Override
82 public Document feed(Document target, CallContext context) { 128 public Document feed(Document target, CallContext context) {
83 try { 129 try {
84 return proxied != null 130 return proxied != null
85 ? proxied.feed(target, context) 131 ? proxied.feed(target, context)
86 : super.feed(target, context); 132 : super.feed(target, context);
88 finally { 134 finally {
89 checkReplacement(context); 135 checkReplacement(context);
90 } 136 }
91 } 137 }
92 138
139 @Override
93 public void out( 140 public void out(
94 Document format, 141 Document format,
95 OutputStream out, 142 OutputStream out,
96 CallContext context 143 CallContext context
97 ) 144 )
108 finally { 155 finally {
109 checkReplacement(context); 156 checkReplacement(context);
110 } 157 }
111 } 158 }
112 159
160 @Override
113 public void endOfLife(Object context) { 161 public void endOfLife(Object context) {
114 if (proxied != null) { 162 if (proxied != null) {
115 proxied.endOfLife(context); 163 proxied.endOfLife(context);
116 } 164 }
117 else { 165 else {
118 super.endOfLife(context); 166 super.endOfLife(context);
119 } 167 }
120 } 168 }
121 169
170 @Override
122 public void cleanup(Object context) { 171 public void cleanup(Object context) {
123 if (proxied != null) 172 if (proxied != null)
124 proxied.cleanup(context); 173 proxied.cleanup(context);
125 else 174 else
126 super.cleanup(context); 175 super.cleanup(context);
127 } 176 }
128 } 177 }
129 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8: 178 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
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