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)); jamai8
} }l]r-
for(int i=0;i<nEndPos.length-1;i++) u|EJ)dT?
{ E6G;fPd= E
nEndPos = nStartPos[i+1]; ]>sMu]biH
} Sqmjf@o$>
nEndPos[nEndPos.length-1] = nFileLength; Y%]g,mG
} 93w$ck},?G
} e*Nm[*@UW
C`3fM05g
^( C,LVP<
//启动子线程 98<^!mwF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c[OQo~m$
for(int i=0;i<nStartPos.length;i++) M5`m5qc3
{ hdM?Uoo(4a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *x2u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3+U2oI:I
nStartPos,nEndPos,i); }gX4dv B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5/m*Lc+r
fileSplitterFetch.start(); Ai)Q(]
} Mwj7*pxUh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {Y]3t9!\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); N;m62N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _A]~`/0;`
nEndPos = " + nFileLength); #LwDs,J:
// fileSplitterFetch[nPos.length-1].start(); B]7QOf"
l`JKQk
g8"{smP/
//等待子线程结束 rHjR 4q
//int count = 0; T z+Y_
//是否结束while循环 MI8c>5?
boolean breakWhile = false; _J3\e%ys
=`gFwH<
KHaYb5(a[
while(!bStop) c1f`?i}.
{ Uf[Gs/!NV
write_nPos(); #?\|)y4i
Utility.sleep(500); )MM(HS
breakWhile = true; )@.ODW;`
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)GC[xo4bg
for(int i=0;i<nStartPos.length;i++) aO\@5i_r
{ dUceZmAl
if(!fileSplitterFetch.bDownOver) Gh'{O/F4*
{ :J5CmU$
breakWhile = false; uk.x1*0x
break; *;.:UR[i
} `5~<)
} U.WMu%
if(breakWhile) k}{K7,DM
break; DB] ]6
d k|X&)xTJ
xU9^8,6
//count++; _j_c&
//if(count>4) &gm/@_
// siteStop(); 1;MUemnx`
} qRZLv7X*j
y=}a55:qE
mO\=#Q>
System.err.println("文件下载结束！"); jin?;v
} r3Ih]|FK#
catch(Exception e){e.printStackTrace ();} D4GXZX8K
} D2#.qoP #
=1F F2#zS
."v&?o Ck]
//获得文件长度 ou&7v<)x4
public long getFileSize() nZS*"O#L
{ gi\UNT9x
int nFileLength = -1; K9'AYFse
try{ $4TawFf"nc
URL url = new URL(siteInfoBean.getSSiteURL()); 2 BwpxV8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X@B,w_b
httpConnection.setRequestProperty("User-Agent","NetFox"); @j4~`~8
eJ$ {`&J
/lvH p
int responseCode=httpConnection.getResponseCode(); aw0xi,Jz
if(responseCode>=400) akA C^:F
{ *:,7 A9LY
processErrorCode(responseCode); s|8_R;
return -2; //-2 represent access is error x"PMi[4
} &nF7CCF
C F<
d4-cZw}+
String sHeader; _$4vk
/E6Tt
DfP vi1
for(int i=1;;i++) +f?xVW<h
{ 3gmu-tv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ps?B;P
//Utility.log(in.readLine()); .gHL(*1P
sHeader=httpConnection.getHeaderFieldKey(i); ,b8B)VZ?
if(sHeader!=null) b;sjw5cm_
{ 1hgmlY`
if(sHeader.equals("Content-Length")) UbV} !
{ Bbx.RL.V
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (z<&PP
break; #bLeK$
} [kq+a]q
} uH!;4@uI
else ;;- I<TL
break; 0bk094
} !ly]{DTmm
} r`/tb^
catch(IOException e){e.printStackTrace ();} =u`^QE
catch(Exception e){e.printStackTrace ();} K29KS)~;W
Ib8xvzR6I&
g8w5X!Z
Utility.log(nFileLength); BI6o@d;=4
?en%m|}0
<:BhV82l
return nFileLength; A@"CrVE
} Lpdp'9>I
/F 1mYq~
}mw31=2bD
//保存下载信息（文件指针位置） 3AD^B\<gB
private void write_nPos() X\1'd,V
{ i'9
try{ jW+L0RkX
output = new DataOutputStream(new FileOutputStream(tmpFile)); "^ cn9AG{
output.writeInt(nStartPos.length); j^~WAWbFh
for(int i=0;i<nStartPos.length;i++) . RNQlh3
{ SQbnn"
// output.writeLong(nPos); yN~: 3
output.writeLong(fileSplitterFetch.nStartPos); Jk7[}Jc$
output.writeLong(fileSplitterFetch.nEndPos); vg1p{^N!
} E8Wgm 8
output.close(); KArnNmJ9
} eESJk14
catch(IOException e){e.printStackTrace ();} X/nb7_M
catch(Exception e){e.printStackTrace ();} 4o2C=?@(
} b-+iL
KdOy3O_5N
q-}J0vu\K
//读取保存的下载信息（文件指针位置） hQgi--Msw'
private void read_nPos() BY$%gIB6>
{ R('44v5JQp
try{ ~Hs a6F&F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~z!U/QR2
int nCount = input.readInt(); NLC}XL
nStartPos = new long[nCount]; E$rn^keM
nEndPos = new long[nCount]; rf8`|9h"7
for(int i=0;i<nStartPos.length;i++) "sRR:wzQu
{ {E`f(9r:
nStartPos = input.readLong(); A:ef}OCL
nEndPos = input.readLong(); PZ;O pp
} MqI!i>
input.close(); S-:l 60.
} T;}pMRd%
catch(IOException e){e.printStackTrace ();} |S:St HZm
catch(Exception e){e.printStackTrace ();} 0BIH.ZV#
} kf$0}T`
@$;"nVZ4v
M(S:&GOU
private void processErrorCode(int nErrorCode) ]#[R^t
{ mY3x (#I
System.err.println("Error Code : " + nErrorCode); m`-{ V<(M
} d7tH~9GX8
H6*d#!
C sn"sf
//停止文件下载 i3>7R'q>
public void siteStop() Zl.}J,0F
{ *B`wQhB%
bStop = true; [3rvRJ.
for(int i=0;i<nStartPos.length;i++) ,y?0Iwf
fileSplitterFetch.splitterStop(); (3"V5r`*;
#G^?4Za
r/fLm8+
} [HK[{M=v=
} dGcG7*EX
//负责部分文件的抓取 (6fh[eK86
**FileSplitterFetch.java xq.,7#3
*/ BxO8oKe
package NetFox; i%0Ml:Y
y#^d8 }+
4S@^ym
import java.io.*; X%S?o
import java.net.*; (~N&ov
Yt7R[|
a!P?RbW
public class FileSplitterFetch extends Thread { <`a!%_LC [
Bi)1*
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String sURL; //File URL }ruBbeQ
long nStartPos; //File Snippet Start Position x2[A(O=
long nEndPos; //File Snippet End Position B9n$8QS
int nThreadID; //Thread's ID IiIF4 pQ,
boolean bDownOver = false; //Downing is over ~(%nnG6x
boolean bStop = false; //Stop identical aDTNr/I
FileAccessI fileAccessI = null; //File Access interface 3xh~xE
d?*=<w!A
'ac %]}`-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M"#xjP.
{ 5R/!e`(m
this.sURL = sURL; k 0z2)3L
this.nStartPos = nStart; x(&o=Pu
this.nEndPos = nEnd; ;2-,Xzz8
nThreadID = id; Q'&oSPXSDd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Qhsh{muw(
} Y:oL
4E}/{1
9#iu#?*B
public void run() |28z4.
{ =h\,-8
while(nStartPos < nEndPos && !bStop) ;dNKe.`Dg
{ &hEtVkK
7g cr$&+e
]4yWcnf
try{ B{lBUv(B
URL url = new URL(sURL); 'q8T*|/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uMtq4.
httpConnection.setRequestProperty("User-Agent","NetFox"); $3|++?
String sProperty = "bytes="+nStartPos+"-"; A$Mmnu%
httpConnection.setRequestProperty("RANGE",sProperty); 2}[)y\`t3
Utility.log(sProperty); vZmM=hW~
U|={LU
ogH{
InputStream input = httpConnection.getInputStream(); Lk6UT)C
//logResponseHead(httpConnection); f3]Z22Yq
I1S*=^Z_U
DDyeNuK
byte[] b = new byte[1024]; L\XnTL{
int nRead; /Zap'S/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9H$#c_zrq
{ X<m#:0iD
nStartPos += fileAccessI.write(b,0,nRead); [*Nuw_l
//if(nThreadID == 1) VChNDHiH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +;tXk
} U@!e&QPn
+LCpE$H
F??})YX
Utility.log("Thread " + nThreadID + " is over!"); o nt8q8
bDownOver = true; <<W{nSm#
//nPos = fileAccessI.write (b,0,nRead); D$d8u=S
} +6-c<m|
catch(Exception e){e.printStackTrace ();} nxkbI:+t
} H[UV]qO,
} -uXf?sTV
D.9qxM"Z>
W~z 2Q so
//打印回应的头信息 +hI:5(_
public void logResponseHead(HttpURLConnection con) Va"Q1 *"
{ fgK1+sW
for(int i=1;;i++) +] >o@
{ Tz[ck'k
String header=con.getHeaderFieldKey(i); [QEV6S]
if(header!=null) \wEHYz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c"Ddw'?e
Utility.log(header+" : "+con.getHeaderField(header)); $n\{6Rwb
else OOn{Wp
break; ov*?[Y7|~
} U}<5%"!;
} tAO,s ZW
U1}-]^\
a,i k=g
public void splitterStop() mZQW>A]iE
{ jT>G8}h
bStop = true; >7i&(6L
} $(/=Wn
_GS_R%b
+e}v)N
} 7yM=$"'d
~(OG3`W!
CT,PQ
/* Yl4XgjG
**FileAccess.java Is1P,`*!
*//文件访问(定位，写) ^)oBa=jL4
package NetFox; viB'ul7o
import java.io.*; ix2V?\
`Y>'*4a\
m:&go2Y
public class FileAccessI implements Serializable{ h|qTMwPr
R8|H*5T?+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @yp#k>
RandomAccessFile oSavedFile; L/\s~*:M
long nPos; ])F*)U
*?bOH5$@Nw
>G7dw1;
public FileAccessI() throws IOException @+Ch2Lod
{ .aS`l~6
this("",0); KUJCkwQ
} mq 0d ea
!\|_,pSB
LCBP9Rftvd
public FileAccessI(String sName,long nPos) throws IOException U9"g;t+/
{ FM$$0}X
oSavedFile = new RandomAccessFile(sName,"rw"); jN))|eD0x
this.nPos = nPos; {txW>rZX
oSavedFile.seek(nPos); kjAARW
} &:Q^j:
t5O '7x
?APzb4f^W
public synchronized int write(byte[] b,int nStart,int nLen) FZL"[3
{ DO*rVs3'p[
int n = -1; M3q%(!2
try{ kU:ge
oSavedFile.write(b,nStart,nLen); tofX.oi+C$
n = nLen; 4eVQO%&2
} [B~*88T
catch(IOException e) de7 \~$
{ +4L]Z;k
e.printStackTrace (); #aI(fQZe
} m\zCHX#n
xER-TT#S
|"]#jx*8KC
return n; {Kh^)oYdd
} Fnqj^5
TAL,(&[s
;|qbz]t2(
} ~jz!jF~I
gXJtk;
v']Tusmg
/* Ei>.eXUD5
**SiteInfoBean.java 1S[4@rZ
*/ U:r^4,Mz*
package NetFox; r+TvC{
'=AqC,\#
GJs{t1 E
public class SiteInfoBean { ._%8H
n4XEyCrD
af@R\"N9c
private String sSiteURL; //Site's URL g)dKXsy(F
private String sFilePath; //Saved File's Path g)!d03Qoy
private String sFileName; //Saved File's Name 6;C2^J@
private int nSplitter; //Count of Splited Downloading File / jLb{Ky
8u%rh[g'
!w1acmo<_
public SiteInfoBean() xiv8q/
{//nSplitter的缺省值为5 -,186ZVZ
//default value of nSplitter is 5 &?@gCVNO,
this("","","",5); y$Fk0s*>
} Gq=tR`.
Prc(
{K N7Y"AI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bV$g]->4e
{ 5Lm-KohT'
sSiteURL= sURL; lb{X6_.
sFilePath = sPath; &( ZEs c
sFileName = sName; QsX`IYk
this.nSplitter = nSpiltter; '2qbIYanh
)Vz=:.D
_BEDQb{"|
} I)\{?LdHR
w1EB>!<;tj
}0Q T5
public String getSSiteURL() 9=J 3T66U
{ }S"qU]>8a
return sSiteURL; hbe";(
} _WGWU7h
vL#I+_ 2
@.,Mn#
public void setSSiteURL(String value) oj=%< a
{ 2Akh/pb
sSiteURL = value; ,Yn$X
} >Qqxn*O
!'C8sNs
SB|Cr:wM
public String getSFilePath() ! o?E.
{ 4d_Az'7`4
return sFilePath; Sim$:5P
} R2==<"gq
dy~M5,zn
;Kh[6{W
public void setSFilePath(String value) >}bkX 6c5
{ |['SiO$)
sFilePath = value; Spw^h=o
} DoNN;^H
HJ!!"
2eRv{_
public String getSFileName() 6>3zD)tG
{ de9e7.(2
return sFileName; zjTCq; G
} \maj5VlJ
x6Tpt^N}
2uT@jfj:r
public void setSFileName(String value) 9e7):ZupO
{ KGf@d*ZOMz
sFileName = value; k$.l^H u
} {z9,CwJan?
qYPgn_
-UWyBM3c@
public int getNSplitter() 7:zoF],s
{ =Qn8Y`U
return nSplitter; iOk`_LG#
} 4QE")Ge
O))j
xouBBb=
public void setNSplitter(int nCount) b)>l7nOc
{ <O41M\,
nSplitter = nCount; QO>)ug+
} _7R6%^
} /IG3>|R
f7a"}.D$
[U$`nnp
/* 3t5WwrNh
**Utility.java e +jp,>(v
*/ RDeI l&
package NetFox; ~iIFe+6
K#N5S]2yb
ZftucD|ZY/
public class Utility { 8/}S/$
Sq5}v]k@&
29W`L2L
public Utility() *CVI@:Q9
{ Snq0OxS[v
-aDBdZ;y
a~k*Gd(
} l xP!WP
{M23a _t\
//线程睡眠 ]>0$l _V
public static void sleep(int nSecond) ;p"#ZS7
{ <^+&A7Q-_
try{ VoyRB2t
Thread.sleep(nSecond); M2A3]wd2a
} oMxpdG3y-
catch(Exception e) &!*p>Ns)e
{ Va/}|&9
e.printStackTrace (); C@MJn)$4
} D7v.Xq|
} L(/wsw~y*
;?gR,AKZ
//日志 r3YfY\
public static void log(String sMsg) '<wZe.Q!
{ kqCUr|M.P
System.err.println(sMsg); m.U&O=]5
} V^\b"1X7N
?aZ\Dg{
<2\QY
public static void log(int sMsg) 2~)q080jh
{ _2<k,Dl;RY
System.err.println(sMsg); P!/:yWd
} Iy2AJ|d.
} I^QB`%v5
QjsN7h&%
pS!N<;OWr
/* ks8xxY
**TestMethod.java F'55BY*!
*/ 7D4I>N'T
package NetFox; U6M&7l8
)7F$:*e
s=XqI@
public class TestMethod { mTa^At"
V/8yW3]Xy
w.Kp[
public TestMethod() w'Jo).OW~
{ ///xx/weblogic60b2_win.exe ZQ~EaI9R
try{ =YR+`[bfI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EkP(]F
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &^ =Y76
SiteFileFetch fileFetch = new SiteFileFetch(bean); P'k`H
fileFetch.start(); %U$%x
} !?m8UE
catch(Exception e){e.printStackTrace ();} 4hV~ ir
ulXe;2
KkZo|\V
} N4,!b_1
WtbOm
YifTC-Q;
public static void main(String[] args) cs)z!
{ pB79#4
new TestMethod(); I\VC2U
} T(bFn?
} y/ah<Y0(
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