http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); eHF(,JI
} R`I8Ud4=
for(int i=0;i<nEndPos.length-1;i++) C }h<ldlY
{ L]/\C{}k
nEndPos = nStartPos[i+1]; wzNt c)~i
} =\ti<
nEndPos[nEndPos.length-1] = nFileLength; "6I-]:K-
} nJ'>#9~a'>
} VurP1@e&
#VQGN2bK.
'-nuH;r
//启动子线程 Ovaj":L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3]:p!Y`$
for(int i=0;i<nStartPos.length;i++) By51dk7
{ UtW"U0A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c{]r{FAx9o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'y+bx?3Z
nStartPos,nEndPos,i); p5twL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x8SM,2ud
fileSplitterFetch.start(); _Cv[`e.
} vUo.BA#;.b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v2Qc}o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a.Rp#}f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,<^tsCI
nEndPos = " + nFileLength); 4t%:O4 3e
// fileSplitterFetch[nPos.length-1].start(); }<}`Q^Mlk
3IJI5K_
YaY;o^11/
//等待子线程结束 !7Yt`l$$z
//int count = 0; Ads<-.R
//是否结束while循环 ^;Hi/KvM\
boolean breakWhile = false; FkJ>]k
!Z+*",]_
xu_XX#9?b
while(!bStop) U'h[{ek
{ ard3yNQt
write_nPos(); 'n>3`1E,
Utility.sleep(500); "dLMBY~
breakWhile = true; lkSz7dr@
,/w852|ub
[FAOp@7W
for(int i=0;i<nStartPos.length;i++) u]]5p[|S
{ [)J49
if(!fileSplitterFetch.bDownOver) #g-*n@ 1
{ L?D~~Jb
breakWhile = false; cvs"WX3
break; A&}nRP9
} r0?hX
} {'c%#\
if(breakWhile) WDH[kJ
break; #8Id:56
z!1/_]WJ,
+EiUAs~H
//count++; [:R P9r}
//if(count>4) q~g&hR}K
// siteStop(); FkxhEat8
} TReM8Vd
T^(n+lv
u\1Wkxj
System.err.println("文件下载结束！"); PGv}fEH"
} d4/`:?w
catch(Exception e){e.printStackTrace ();} KWigMh\r
} zZ+LisSs&
Q:fUM[
YP\4XI
//获得文件长度 Ng_rb KXC#
public long getFileSize() \}4#**]
{ %:be{Y6
int nFileLength = -1; RZ/+K=
try{ ]=86[A-2N
URL url = new URL(siteInfoBean.getSSiteURL()); UTK.tg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ev;5?9\E
httpConnection.setRequestProperty("User-Agent","NetFox"); "-j@GCme
O%++0k;
Pdo5sve
int responseCode=httpConnection.getResponseCode(); {HRxyAI!
if(responseCode>=400) A^r [_dyZ
{ *F8uu.
processErrorCode(responseCode); C!/8e (!N
return -2; //-2 represent access is error ".Deu|>
} ^?^|Y?f2P?
dn)tP6qc/
H:{(CY?t
String sHeader; k+Ma_H`
i:Z.;z$1
QhE("}1
for(int i=1;;i++) ]N(zom_0d
{ Dpp52UnTE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ng;b!S
//Utility.log(in.readLine()); d$?n6|4
sHeader=httpConnection.getHeaderFieldKey(i); ,f/IG.
if(sHeader!=null) _"w!KNX>(~
{ ++{+ #s6
if(sHeader.equals("Content-Length")) s<r.+zqW
{ sm&rR=b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CO%O<_C
break; &A5[C{x
} Jn:GA@[I
} 3d)+44G_)
else {R{%Z
break; _OxnHf:|
} .&yWHdQC:
} -_4jJxh=OB
catch(IOException e){e.printStackTrace ();} jf)JPa_
catch(Exception e){e.printStackTrace ();} $evuPm8G
Y'a(J7
O*n%2Mam
Utility.log(nFileLength); @n;YF5
1d@^,7MF-
J>|:T
return nFileLength; %k;FxUKi
} yYg&'3
DIu72\
gmAKW4(
//保存下载信息（文件指针位置） 4#7@KhK}
private void write_nPos() g`8 mh&u%
{ dBq,O%$oq
try{ h9n<ped`A;
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?L#SnnE
output.writeInt(nStartPos.length); 1yRd10
for(int i=0;i<nStartPos.length;i++) l;VGJMPi
{ cV!/
// output.writeLong(nPos); (_n8$3T75
output.writeLong(fileSplitterFetch.nStartPos); l<K.!z<-:8
output.writeLong(fileSplitterFetch.nEndPos); h}%M
} "KTnX#<0
output.close(); {FmFu$z+[
} c%3 @J+z
catch(IOException e){e.printStackTrace ();} 53&xTcv}x
catch(Exception e){e.printStackTrace ();} zUgkY`]:BJ
} G-i_s6Wu
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n_Hnk4
//读取保存的下载信息（文件指针位置） ]aW.b_7<9
private void read_nPos() w*ktx{
{ &fy8,}
try{ Joo)GIB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .6/p4OR|
int nCount = input.readInt(); |2&mvjk@H
nStartPos = new long[nCount]; <@j
nEndPos = new long[nCount]; Uus)2R7
for(int i=0;i<nStartPos.length;i++) %Kfa|&'zV
{ KeOBbe
nStartPos = input.readLong(); K$vRk5U
nEndPos = input.readLong(); n|,Vm@zV
} MGC0^voe
input.close(); ,Y5 4(>>%
} #<>E+r+
catch(IOException e){e.printStackTrace ();} zr9Pm6Rl
catch(Exception e){e.printStackTrace ();} qlT:9*&g
} fU~y481A
NGQIoKC
]{U*+K%,J
private void processErrorCode(int nErrorCode) l45F*v]^
{ i&Cqw~.H
System.err.println("Error Code : " + nErrorCode); \*"0wR;[K
} 4sE=WPKF#
F"#*8P
O xaua
//停止文件下载 4wD^?S!p
public void siteStop() EGr5xR-
{ k+G4<qw
bStop = true; ZU@jtqq
for(int i=0;i<nStartPos.length;i++) ~9;mZi1-
fileSplitterFetch.splitterStop(); 8A]q!To
;B7|tajd
"lzg@=$|)
} 5e8-?w%e
} iw;Alav"x
//负责部分文件的抓取 CrX-?$
**FileSplitterFetch.java ?iO^b.'I#
*/ (y4Eq*n%!
package NetFox; cW/~4.v$
g^^m a}i
C4TD@
import java.io.*; Ip\g^ia
import java.net.*; ]b=A/*z
54_m{&hb
*YOnX7*Km
public class FileSplitterFetch extends Thread { 8-6{MJ?F
vKLG9ovlY
F qyJ*W\1
String sURL; //File URL Ec/+9H6g
long nStartPos; //File Snippet Start Position 'N/%SRk
long nEndPos; //File Snippet End Position JkEQ@x
int nThreadID; //Thread's ID -;.fU44O[#
boolean bDownOver = false; //Downing is over }(O kl1
boolean bStop = false; //Stop identical 1L9 <1
FileAccessI fileAccessI = null; //File Access interface *4\ub:9
#!j&L6
sJYX[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jo:p*Q"F
{ bbA<Zp
this.sURL = sURL; j*\MUR=
this.nStartPos = nStart; )p](*Z^
this.nEndPos = nEnd; GDe$p;#"9g
nThreadID = id; >%A=b}VS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y{{,62D
} Du4?n8 o
*Y>'v%
fkG"72 95A
public void run() L7="!I
{ r2`?Ta
while(nStartPos < nEndPos && !bStop) aq**w?l
{ TK1MmL
5Z0x2jV
F&Z>B};
try{ N.J:Qn`(
URL url = new URL(sURL); EE{%hGb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sAj$U^Gp
httpConnection.setRequestProperty("User-Agent","NetFox"); 1x8]&
String sProperty = "bytes="+nStartPos+"-"; (VRnv
httpConnection.setRequestProperty("RANGE",sProperty); a[#BlH
Utility.log(sProperty); tjL#?j
wQ95tN
y!Eh /KD
InputStream input = httpConnection.getInputStream(); bJvRQrj*3
//logResponseHead(httpConnection); cZi&L p
artS*fv3r
@XJv9aq
byte[] b = new byte[1024]; MQI=
int nRead; VAz+J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !1]xKNp]
{ eVJL|uI|
nStartPos += fileAccessI.write(b,0,nRead); ";%1sK
//if(nThreadID == 1) V6o,}o&-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R'_[RHFC
} RAa1KOxZX
-#hl&^u$
d@~)Wlje
Utility.log("Thread " + nThreadID + " is over!"); #-8/|_*
bDownOver = true; zoXF"Nz
//nPos = fileAccessI.write (b,0,nRead); 3?<vnpN=5d
} ,s<d"]<
catch(Exception e){e.printStackTrace ();} Yi,um-%
} X13bi}O6#
} ]z$<6+G
+d.Bf
06r cW `
//打印回应的头信息 IrK )N
public void logResponseHead(HttpURLConnection con) Z%{2/mQ
{ '1IH^<b
for(int i=1;;i++) i;7jJ(#V
{ l$NEx0Dffz
String header=con.getHeaderFieldKey(i); e;v2`2z2
if(header!=null) {643Dz<e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'McVaPav
Utility.log(header+" : "+con.getHeaderField(header)); T!AQJ:;1
else A#{*A
break; o!N@W
} *0tNun 5=3
} r>OE[C69
9)`wd&!
_;+&'=6.[
public void splitterStop() :I8t}Wg
{ 1,,:4*)
bStop = true; 37DvI&
} SJmri]4K
23m+"4t
Obm\h*$
} :>u{BG;=79
TW$^]u~v
G{9y`;
/* {0~ p"%*
**FileAccess.java e78}
*//文件访问(定位，写) 6I<`N
package NetFox; ^ +G> N
import java.io.*; ud1E@4;qf
?6gI8K6X
[DviN
public class FileAccessI implements Serializable{ mE1*F'0a
xMu6PM<l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -`JY] H
RandomAccessFile oSavedFile; N_U D7P1
long nPos; nDfDpP&
?M);wBe(
-b<+Ra
public FileAccessI() throws IOException 1{qg@xlj
{ Y2fs$emv
this("",0); A}o1I1+
} \hVFK6
r0,}f\
F$v G=3
public FileAccessI(String sName,long nPos) throws IOException |b'AWI81D
{ w67Pw
oSavedFile = new RandomAccessFile(sName,"rw"); H}/1/5L
this.nPos = nPos; }OZfsYPz}T
oSavedFile.seek(nPos); d p].FS
} qp8;=Nfa
+a{>jzR
P^z)]K#sw
public synchronized int write(byte[] b,int nStart,int nLen) 4-AmzU
{ Qoc-ZC"<6
int n = -1; i@6 kIC
try{ uQ}kq7gd
oSavedFile.write(b,nStart,nLen); !{+(oDN
n = nLen; &^"m6
} Y\\&~g42R2
catch(IOException e) DBRTZES
{ ,k4 (b
e.printStackTrace (); BC3I{Y|
} d*(1t\
00ho*p!E'
@W8RAS~
return n; YI/vt2
} 8GX@76o
>8c9-dTmf
4f+Ke*^[RA
} xE:p)B-]
:v+39
o_S8fHqjt
/* `%VrT`
**SiteInfoBean.java 6mZFsB
*/ .nnAI@7E
package NetFox; _nF_RpS
JL1Whf
M~v{\!S
public class SiteInfoBean { d] {^
X#fI$9a
Cs<d\"+
private String sSiteURL; //Site's URL $Khc?v
private String sFilePath; //Saved File's Path oVs&r?\Z
private String sFileName; //Saved File's Name `R\0g\
private int nSplitter; //Count of Splited Downloading File :?zOLw?(
1*s Lj#
@d)6LA9Ec
public SiteInfoBean() q;U[f6JjE
{//nSplitter的缺省值为5 aV1(DZ83
//default value of nSplitter is 5 MQ01!Y[q_7
this("","","",5); 4GJsVA(d|
} ~*RNJ
h c"n?
3OTSLF/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #'8E%4
{ 6<2 7}S
sSiteURL= sURL; <7qM;)g
sFilePath = sPath; $8b/"Qm
sFileName = sName; k;]&`c^5
this.nSplitter = nSpiltter; 0@>3fR
9d v+u6)
"&An9H'
} $WDa}~j~^
B<W{kEY
2`x[y?Tn
public String getSSiteURL() 3a =KgOvp
{ ^z_~e@U
return sSiteURL; FQ_4a}UOjX
} ke/QFN-`
9G&l{7=
<)&;9C
public void setSSiteURL(String value) 3K{'~?mM
{ Bb m1&d#
sSiteURL = value; >n#Pq{7aF
} .Sm7na K
i=Y#kL~f
0-7xcF@s
public String getSFilePath() #P1k5!u
{ B>Mk "WjQ
return sFilePath; =OCHV+m
} +Oo>V~
{'JoVJKv
v~j21`
public void setSFilePath(String value) |]V0sgpoZ
{ \S _ycn
sFilePath = value; (@]{=q<
} ~G"5!,J
!pgkUzMW
|iU#!+zY
public String getSFileName() `Q,03W#GJ%
{ xGN&RjPk\
return sFileName; X ZfT;!wF&
} zUWu5JI
8|gwH2st~
@hp@*$#& 9
public void setSFileName(String value) E`BL3+kQ
{ ka655O/)&
sFileName = value; #49,7OBU
} JpN+'/
4~DoqT
N|wI=To
public int getNSplitter() @xR=bWY
{ 074)(X&:x
return nSplitter; kLK}N>v}X
} VXQ~PF]z0
W2s6!_AN
Ft'?43J
public void setNSplitter(int nCount) Y'wQ(6ok
{ yi PMJ
nSplitter = nCount; THC34u]
} R0vWj9nPh
} B\`4TU}kE
4vF1
wP29xV"5
/* y\]:&)?&C^
**Utility.java ,iV|^]X3$/
*/ _O{3bIay3!
package NetFox; Z)?B5FF
>yiK&LW^?
:T.j;~
public class Utility { e2~&I`ct
N2WQrTA:S+
"6o}g.
public Utility() U,\3 !D0jt
{ Q#i[Y?$L
DHQavHqbZ
ly9.2<oz}L
} >La!O~d
1?\G6T
//线程睡眠 yP.,Dh s
public static void sleep(int nSecond) !/2uO5
{ d?)k<!fJk
try{ _XvSe]`f`
Thread.sleep(nSecond); 5=(fuY3
} Y {a#2(xn
catch(Exception e) u[k0z!p_ c
{ yL{X}:;}
e.printStackTrace (); (hr*.NS#
} Fu].%`*xJ
} ):-\TVz~
06X4mu{
//日志 R<}UT
public static void log(String sMsg) A%(t'z
{ &?59{B.mD
System.err.println(sMsg); :(ni/,~Q
} TL'^@Y7X5
g$+ $@~
j6}/pe*;;T
public static void log(int sMsg) O!xul$9
{ N;gI %6
System.err.println(sMsg); }&!fT\4
} @'P\c
} /r2*le (H
d|I?%LX0p
kzozjh%`9h
/* iW oe
**TestMethod.java |T3F:],`
*/ m%7T ~
package NetFox; I8M^]+c
7 G37V"''
20h+^R3{Z
public class TestMethod { II;
<l>o6K
?9W2wqN>o
public TestMethod() J7a_a>Y
{ ///xx/weblogic60b2_win.exe mQwP-s
try{ LlbRr.wL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4}&$s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D6z*J?3^#&
SiteFileFetch fileFetch = new SiteFileFetch(bean); $1KvL8
fileFetch.start(); cug=k
} P~xP@?I%
catch(Exception e){e.printStackTrace ();} _e4%<!1
xWR<>Og.
A-S!Z2m\
} a>6@1liT
mLGbwm'K
S1SsJo2\
public static void main(String[] args) | 6/ # H*
{ }:SWgPfc
new TestMethod(); (58}G2}q
} $<DcbJW
} m6wrG`-di
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