回答編集履歴
2
factory ではなく builder
test
CHANGED
|
@@ -35,18 +35,18 @@
|
|
|
35
35
|
|
|
36
36
|
SortTest readFrom(String filename) throws FileNotFoundException, IOException { //throws で例外時の処理は呼び出し側に任せる
|
|
37
37
|
persons.clear();
|
|
38
|
-
Person.
|
|
38
|
+
Person.Builder builder = new Person.Builder();
|
|
39
39
|
try(BufferedReader reader = new BufferedReader(new FileReader(filename))) { //try-with-resource ( close が自動的 )
|
|
40
40
|
for(String line; (line=reader.readLine()) != null; ) { //'readLine' の結果を受ける変数名は 'line' のほうが合ってる感じ. そして変数の有効範囲(スコープ)は狭く
|
|
41
41
|
String[] tokens = line.split(",");
|
|
42
42
|
try {
|
|
43
43
|
if(tokens.length == 4) {
|
|
44
|
-
persons.add(
|
|
44
|
+
persons.add(builder
|
|
45
45
|
.setId(tokens[0])
|
|
46
46
|
.setName(tokens[1])
|
|
47
47
|
.setBirthday(tokens[2])
|
|
48
48
|
.setGender(tokens[3])
|
|
49
|
-
.
|
|
49
|
+
.build());
|
|
50
50
|
} else {
|
|
51
51
|
throw new IllegalStateException("データが4つでは無い. tokens.length="+tokens.length);
|
|
52
52
|
}
|
|
@@ -77,30 +77,30 @@
|
|
|
77
77
|
//birthday の解析/表示用
|
|
78
78
|
private static final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy/MM/dd");
|
|
79
79
|
|
|
80
|
-
static class
|
|
80
|
+
static class Builder { //Person の生成はこのクラスが行う
|
|
81
81
|
private int id;
|
|
82
82
|
private String name;
|
|
83
83
|
private LocalDate birthday;
|
|
84
84
|
private Gender gender;
|
|
85
85
|
|
|
86
|
-
|
|
86
|
+
Builder setId(String id) {
|
|
87
87
|
this.id = Integer.parseInt(id);
|
|
88
88
|
return this; //自身を返すことで、呼び出し側が '.' で複数のメソッドを繋げて書けるようになる
|
|
89
89
|
}
|
|
90
|
-
|
|
90
|
+
Builder setName(String name) {
|
|
91
91
|
if(name == null) throw new NullPointerException();
|
|
92
92
|
this.name = name;
|
|
93
93
|
return this;
|
|
94
94
|
}
|
|
95
|
-
|
|
95
|
+
Builder setBirthday(String birthday) {
|
|
96
96
|
this.birthday = LocalDate.parse(birthday, formatter);
|
|
97
97
|
return this;
|
|
98
98
|
}
|
|
99
|
-
|
|
99
|
+
Builder setGender(String gender) {
|
|
100
100
|
this.gender = Gender.valueOf(gender);
|
|
101
101
|
return this;
|
|
102
102
|
}
|
|
103
|
-
Person
|
|
103
|
+
Person build() {
|
|
104
104
|
return new Person(id, name, birthday, gender);
|
|
105
105
|
}
|
|
106
106
|
}
|
|
@@ -110,7 +110,7 @@
|
|
|
110
110
|
final LocalDate birthday;
|
|
111
111
|
final Gender gender;
|
|
112
112
|
|
|
113
|
-
private Person(int id, String name, LocalDate birthday, Gender gender) {
|
|
113
|
+
private Person(int id, String name, LocalDate birthday, Gender gender) {
|
|
114
114
|
this.id = id;
|
|
115
115
|
this.name = name;
|
|
116
116
|
this.birthday = birthday;
|
1
コード追加
test
CHANGED
|
@@ -8,4 +8,149 @@
|
|
|
8
8
|
Collections.sort(sortbeanArray, new MemberComparator());
|
|
9
9
|
for (int i = 0; i < sortbeanArray.size(); i++) {
|
|
10
10
|
```
|
|
11
|
+
---
|
|
12
|
+
勉強用なら、 TN8001 さんと違った方向のコードにしてみます。
|
|
13
|
+
```java
|
|
14
|
+
import java.io.*;
|
|
15
|
+
import java.time.LocalDate;
|
|
16
|
+
import java.time.format.DateTimeFormatter;
|
|
17
|
+
import java.util.*;
|
|
11
18
|
|
|
19
|
+
public class SortTest {
|
|
20
|
+
public static void main(String[] args) {
|
|
21
|
+
try {
|
|
22
|
+
new SortTest()
|
|
23
|
+
.readFrom("meibo.txt") //ファイル名は埋め込むよりパラメータで渡す
|
|
24
|
+
.show("■ ソートせずに一覧表示")
|
|
25
|
+
.sort((a,b) -> a.id < b.id ? -1 : a.id > b.id ? 1 : 0) //ラムダ式 & 三項演算子
|
|
26
|
+
.show("■ IDでソートし一覧表示");
|
|
27
|
+
} catch(FileNotFoundException e) {
|
|
28
|
+
System.out.println("ファイルが見つかりません."+e.getMessage());
|
|
29
|
+
} catch(IOException e) {
|
|
30
|
+
System.out.println("ファイルの読み込みで問題が発生しました. "+e.getMessage());
|
|
31
|
+
}
|
|
32
|
+
}
|
|
33
|
+
|
|
34
|
+
private List<Person> persons = new ArrayList<>();
|
|
35
|
+
|
|
36
|
+
SortTest readFrom(String filename) throws FileNotFoundException, IOException { //throws で例外時の処理は呼び出し側に任せる
|
|
37
|
+
persons.clear();
|
|
38
|
+
Person.Factory factory = new Person.Factory();
|
|
39
|
+
try(BufferedReader reader = new BufferedReader(new FileReader(filename))) { //try-with-resource ( close が自動的 )
|
|
40
|
+
for(String line; (line=reader.readLine()) != null; ) { //'readLine' の結果を受ける変数名は 'line' のほうが合ってる感じ. そして変数の有効範囲(スコープ)は狭く
|
|
41
|
+
String[] tokens = line.split(",");
|
|
42
|
+
try {
|
|
43
|
+
if(tokens.length == 4) {
|
|
44
|
+
persons.add(factory
|
|
45
|
+
.setId(tokens[0])
|
|
46
|
+
.setName(tokens[1])
|
|
47
|
+
.setBirthday(tokens[2])
|
|
48
|
+
.setGender(tokens[3])
|
|
49
|
+
.create());
|
|
50
|
+
} else {
|
|
51
|
+
throw new IllegalStateException("データが4つでは無い. tokens.length="+tokens.length);
|
|
52
|
+
}
|
|
53
|
+
} catch(Exception e) {
|
|
54
|
+
System.out.println("format error. line="+line);
|
|
55
|
+
e.printStackTrace(); //例外の詳細の表示はコレ
|
|
56
|
+
}
|
|
57
|
+
}
|
|
58
|
+
}
|
|
59
|
+
System.out.println("読み込み完了");
|
|
60
|
+
return this;
|
|
61
|
+
}
|
|
62
|
+
|
|
63
|
+
SortTest sort(Comparator<Person> comparator) {
|
|
64
|
+
Collections.sort(persons, comparator);
|
|
65
|
+
return this;
|
|
66
|
+
}
|
|
67
|
+
|
|
68
|
+
SortTest show(String header) {
|
|
69
|
+
System.out.println(header);
|
|
70
|
+
for(Person person : persons) System.out.println(""+person);
|
|
71
|
+
return this;
|
|
72
|
+
}
|
|
73
|
+
|
|
74
|
+
private static class Person {
|
|
75
|
+
enum Gender { Male, Female } //少ない選択肢なら enum
|
|
76
|
+
|
|
77
|
+
//birthday の解析/表示用
|
|
78
|
+
private static final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy/MM/dd");
|
|
79
|
+
|
|
80
|
+
static class Factory { //ファクトリパターン (Person の生成はこのクラスが行う)
|
|
81
|
+
private int id;
|
|
82
|
+
private String name;
|
|
83
|
+
private LocalDate birthday;
|
|
84
|
+
private Gender gender;
|
|
85
|
+
|
|
86
|
+
Factory setId(String id) {
|
|
87
|
+
this.id = Integer.parseInt(id);
|
|
88
|
+
return this; //自身を返すことで、呼び出し側が '.' で複数のメソッドを繋げて書けるようになる
|
|
89
|
+
}
|
|
90
|
+
Factory setName(String name) {
|
|
91
|
+
if(name == null) throw new NullPointerException();
|
|
92
|
+
this.name = name;
|
|
93
|
+
return this;
|
|
94
|
+
}
|
|
95
|
+
Factory setBirthday(String birthday) {
|
|
96
|
+
this.birthday = LocalDate.parse(birthday, formatter);
|
|
97
|
+
return this;
|
|
98
|
+
}
|
|
99
|
+
Factory setGender(String gender) {
|
|
100
|
+
this.gender = Gender.valueOf(gender);
|
|
101
|
+
return this;
|
|
102
|
+
}
|
|
103
|
+
Person create() {
|
|
104
|
+
return new Person(id, name, birthday, gender);
|
|
105
|
+
}
|
|
106
|
+
}
|
|
107
|
+
|
|
108
|
+
final int id; //final にすると変更出来なくなる
|
|
109
|
+
final String name;
|
|
110
|
+
final LocalDate birthday;
|
|
111
|
+
final Gender gender;
|
|
112
|
+
|
|
113
|
+
private Person(int id, String name, LocalDate birthday, Gender gender) { //Factory が生成する為 private
|
|
114
|
+
this.id = id;
|
|
115
|
+
this.name = name;
|
|
116
|
+
this.birthday = birthday;
|
|
117
|
+
this.gender = gender;
|
|
118
|
+
}
|
|
119
|
+
|
|
120
|
+
@Override
|
|
121
|
+
public String toString() { //表示用の文字列を自分で生成する
|
|
122
|
+
return String.join(",",""+id,name,birthday.format(formatter),""+gender);
|
|
123
|
+
}
|
|
124
|
+
}
|
|
125
|
+
}
|
|
126
|
+
```
|
|
127
|
+
meibo.txt
|
|
128
|
+
```plain
|
|
129
|
+
57,田中,1999/11/11,Male
|
|
130
|
+
25,山田,1970/03/12,Female
|
|
131
|
+
33,伊藤,1989/05/01,Female
|
|
132
|
+
49,斎藤,2000/01/12,Male
|
|
133
|
+
50,杉山,2010/05/05,Male
|
|
134
|
+
63,河井,1996/01/30,Female
|
|
135
|
+
5,松田,1989/03/21,Male
|
|
136
|
+
```
|
|
137
|
+
実行結果
|
|
138
|
+
```plain
|
|
139
|
+
読み込み完了
|
|
140
|
+
■ ソートせずに一覧表示
|
|
141
|
+
57,田中,1999/11/11,Male
|
|
142
|
+
25,山田,1970/03/12,Female
|
|
143
|
+
33,伊藤,1989/05/01,Female
|
|
144
|
+
49,斎藤,2000/01/12,Male
|
|
145
|
+
50,杉山,2010/05/05,Male
|
|
146
|
+
63,河井,1996/01/30,Female
|
|
147
|
+
5,松田,1989/03/21,Male
|
|
148
|
+
■ IDでソートし一覧表示
|
|
149
|
+
5,松田,1989/03/21,Male
|
|
150
|
+
25,山田,1970/03/12,Female
|
|
151
|
+
33,伊藤,1989/05/01,Female
|
|
152
|
+
49,斎藤,2000/01/12,Male
|
|
153
|
+
50,杉山,2010/05/05,Male
|
|
154
|
+
57,田中,1999/11/11,Male
|
|
155
|
+
63,河井,1996/01/30,Female
|
|
156
|
+
```
|