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)); I1<WHq
} A=N$5ZJ
for(int i=0;i<nEndPos.length-1;i++) pa>C}jk}6
{ 5CY%h
nEndPos = nStartPos[i+1]; m+(Cl#+
} l f>/
nEndPos[nEndPos.length-1] = nFileLength; 6("_}9ZOc
} $mQ0w~:@
} f^F;`;z
P 45Irir
N"70P/
//启动子线程 42dv3bE"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mwAN9<o
for(int i=0;i<nStartPos.length;i++) [HILK`@@
{ d[a(uWEl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QG5WsuT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EvT$|#FY
nStartPos,nEndPos,i); LF7-??'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &6sF wK
fileSplitterFetch.start(); 0AB a&'h
} \L Q+ n+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )3h\QE!z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c1f"z1Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _Y; TS1u
nEndPos = " + nFileLength); #mQ@4k9i
// fileSplitterFetch[nPos.length-1].start(); UoT`/.
`zQuhD 8W
@c|=onx5
//等待子线程结束 ^k6_j\5j
//int count = 0; -XBZ1q
//是否结束while循环 !ho^:}m
boolean breakWhile = false; 26j<>>2
dtTn]}J
6`e{l+c=F
while(!bStop) ~,)jZ-fw
{ !rnjmc
write_nPos(); -xtT,^<B
Utility.sleep(500); OUBGbld
breakWhile = true; tMl y*E
Ju+3}
tYjG8P#
for(int i=0;i<nStartPos.length;i++) u^2`$W
{ rS1gFGrj
if(!fileSplitterFetch.bDownOver) U)(R4Y6 v
{ e;.,x 5+
breakWhile = false; 't<iB&wgF
break; ~5HkDtI)
} Wdd}y`lS
} w.m8SvS&b
if(breakWhile) r^ r+h[V
break; 2C S9v
_U~R
/M2in]oH
//count++; <nk|Z'G E
//if(count>4) j97+'AKX
// siteStop(); \[G'cE
} Ca |}i+
:2/L1A)O
FvsVfV U
System.err.println("文件下载结束！"); 88?bUA3]
} lelmX
catch(Exception e){e.printStackTrace ();} 0,hs%x>v
} {~apY,3
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n.+*_c8k
//获得文件长度 Iy)1(upM
public long getFileSize() x1:mT[[$
{ I9kz)Q o
int nFileLength = -1; #S7oW@
try{ 0AM_D >fH
URL url = new URL(siteInfoBean.getSSiteURL()); Cmx<>7fN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2Bt/co-~4
httpConnection.setRequestProperty("User-Agent","NetFox"); ?+}Su'pv}
c]pz&
SK}jhm"y
int responseCode=httpConnection.getResponseCode(); 19fa7E<
if(responseCode>=400) >Tf}aI+
{ C^q|(G)
processErrorCode(responseCode); 8~!E.u9w
return -2; //-2 represent access is error ?8 }pZ_j
} Ti2cD
t|@5,J
HxbzFu?h
String sHeader; c =m#MMc)
CVO_F=;
EC,,l'%a|/
for(int i=1;;i++) HQ+{9Z8 ?5
{ mAlG}<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M8H hjoo
//Utility.log(in.readLine()); bZ`#;D<
sHeader=httpConnection.getHeaderFieldKey(i); $z!G%PO1%
if(sHeader!=null) +c8`N'~
{ (H:c80/V
if(sHeader.equals("Content-Length")) _4oAk @A
{ Pz50etJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NFVu~t
break; 3?E7\\/R
} +xuv+mo
} p7\LLJ y
else xR-;,=J
break; }/J"/ T
} jA"}\^%3
} KY&Lv^1_|
catch(IOException e){e.printStackTrace ();} o"Xv)#g&
catch(Exception e){e.printStackTrace ();} =?|$}vDO[
OK4r)
7s^b@&Le
Utility.log(nFileLength); 3^KR{N p
uWx<J3~q.
L%H\|>k`
return nFileLength; Wm1dFf.>
} ]$#bNt/p
?"'+tZ=f6
z1b@JCWE
//保存下载信息（文件指针位置） H%vgPQ8
private void write_nPos() E3a^"V3p
{ sm"Rp~[i
try{ ~5Fx[q
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'g<"@SS+
output.writeInt(nStartPos.length); 2r2:
for(int i=0;i<nStartPos.length;i++) !>'A2V~F
{ C_3,|Zq?|
// output.writeLong(nPos); B _ J2Bf
output.writeLong(fileSplitterFetch.nStartPos); XRV~yBIS
output.writeLong(fileSplitterFetch.nEndPos); qbQdxKk
} X\BFvSv8C
output.close(); -5v{p
} 4,@jSr|I3i
catch(IOException e){e.printStackTrace ();} \DlMOG
catch(Exception e){e.printStackTrace ();} 3\]j4*i!
} $$Tf1hIg
LRw-I.z
uo?R;fX26
//读取保存的下载信息（文件指针位置） 3w>1R>7
private void read_nPos() mph9/ %]S
{ ^d# AU7V|
try{ G_qt~U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Lo}T%0"G
int nCount = input.readInt(); )Pubur %,
nStartPos = new long[nCount]; !r6Yq,3
nEndPos = new long[nCount]; hVyeHbx
for(int i=0;i<nStartPos.length;i++) IR3+BDE)>
{ ts@w9|
nStartPos = input.readLong(); >bI\pJ
nEndPos = input.readLong(); UdcV<#
} 1fV)tvU$
input.close(); Zcw<USF8
} %p7onwKq0
catch(IOException e){e.printStackTrace ();} /?j kVy*"
catch(Exception e){e.printStackTrace ();} Migl
} XL44pE m
./zzuKO8XK
YnU*MC}
private void processErrorCode(int nErrorCode) ,c`Wmp^AY
{ Kc@Sw{JR#7
System.err.println("Error Code : " + nErrorCode); JoG(Nk]
} vV=rBO0a?
O`!XW8
sUQ Q/F6
//停止文件下载 v=dK2FaY
public void siteStop() cM,g,E}
{ zFDtC-GF
bStop = true; hW~UJ/$
for(int i=0;i<nStartPos.length;i++) *aFh*-Sj2I
fileSplitterFetch.splitterStop(); oO7)7$|1
}Q\+w,pJgN
p Djt\R<f
} 9GT}_ ^fb
} ePR9r}
//负责部分文件的抓取 A42!%>PB
**FileSplitterFetch.java r}(mjC"o
*/ n _x+xVi%
package NetFox; *c%{b3T_
m;1/+qs0
GjN6Af~}
import java.io.*; Lr d-
import java.net.*; VV54$a
8}AWU
[wJ\.9<Oa
public class FileSplitterFetch extends Thread { 9@mvG^
f`}/^*D
1D!MXYgm1b
String sURL; //File URL }7xcHVO8-
long nStartPos; //File Snippet Start Position H?ug-7k/
long nEndPos; //File Snippet End Position $-jj%kS
int nThreadID; //Thread's ID z yp3+|
boolean bDownOver = false; //Downing is over Wi,)a{
boolean bStop = false; //Stop identical LylCr{s7
FileAccessI fileAccessI = null; //File Access interface 0V86]zSo
j/NX
2}*8( 32
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }L%2K"8?}
{ ?1O` Rd{tn
this.sURL = sURL; r1}1lJ>7H
this.nStartPos = nStart; Aeo=m}C;
this.nEndPos = nEnd; yh|+Usa
nThreadID = id; xsy45az<ip
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g>gf-2%Uo
} to1r 88X
C?W}/r[
zuFPG{^\#
public void run() Oz&*A/si+3
{ 5DkEJk7a
while(nStartPos < nEndPos && !bStop) 7[K3kUm[
{ @6aJh< c
iTT%_-X-
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try{ 2|WM?V&
URL url = new URL(sURL); \I<R.49oW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m~P30)
httpConnection.setRequestProperty("User-Agent","NetFox"); rO{?.#~
String sProperty = "bytes="+nStartPos+"-"; 5v`lCu]
httpConnection.setRequestProperty("RANGE",sProperty); Ho[]03
Utility.log(sProperty); 1,]FLsuy
ro3%VA=V
\j BA4?(S
InputStream input = httpConnection.getInputStream(); D/;[x{;E
//logResponseHead(httpConnection); NpKyrXDJv
AGjjhbGB
guf*>qNr
byte[] b = new byte[1024]; Dfc% jWbA
int nRead; ]%FP*YU4O
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z}Us+>z+jc
{ F;kKn:XL
nStartPos += fileAccessI.write(b,0,nRead); VN\VTSZh?\
//if(nThreadID == 1) ^,5%fl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PX2b(fR8_O
} ~ISY( &
-Lb7=98
:*DWL!a
Utility.log("Thread " + nThreadID + " is over!"); P>_9>k@;Q
bDownOver = true; %B1)mA;
//nPos = fileAccessI.write (b,0,nRead); T}29(xz-(h
} W,H=K##6<
catch(Exception e){e.printStackTrace ();} qbCU&G|)
} ,=c(P9}^
} [u^ fy<jdp
TA:uB[Ji
fE&s 6w&
//打印回应的头信息 }aI>dHL
public void logResponseHead(HttpURLConnection con) >H5t,FfQL
{ VlSM/y5
for(int i=1;;i++) z 0zB&}
{ #3{}(T7
String header=con.getHeaderFieldKey(i); I&gd"F _v}
if(header!=null) s,!vBSn8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +Wy`X5v
Utility.log(header+" : "+con.getHeaderField(header)); B!8X?8D
else {D :WXvI
break; "!7Hu7
} SDNRcSbOD6
} _*8 6
BYHyqpP9
r$'.$k\
public void splitterStop() ,O:p`"3`0=
{ @,;h!vB*=
bStop = true; |`Yn'Mj8rm
} P>)J:.tr0
(: kn)
f7!48,(fB
} }R5EuR m\
92.Rjz;=9?
8g-Z~~0W1
/* C.LAr~P
**FileAccess.java {D(l#;,iX2
*//文件访问(定位，写) MtF0/aT
package NetFox; NV?XZ[<*<
import java.io.*; ZqpK}I
v*.iNA;&i
V>Xg\9B_
public class FileAccessI implements Serializable{ n5BD0q
CyHHV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G|-RscPe
RandomAccessFile oSavedFile; f#!nj]}#
long nPos; \v<S:cTf
G/fBeK$.
>=:mtcph
public FileAccessI() throws IOException )p>p3b g
{ w'$>E4\
this("",0); ~&F|g2:
} B"#pvJN
3vAP&i'I
z j#<X
public FileAccessI(String sName,long nPos) throws IOException u;1[_~
{ n_LK8
oSavedFile = new RandomAccessFile(sName,"rw"); 'NfsAE
this.nPos = nPos; Fs=x+8'M
oSavedFile.seek(nPos); !Y7$cU &
} 4MW oGV9
wxj}k7_(`A
#*"V'dj;e
public synchronized int write(byte[] b,int nStart,int nLen) v3t<rv
{ Iw( wT_
int n = -1; T\6,@7
try{ vSoG] :1
oSavedFile.write(b,nStart,nLen); \pTC[Ry1
n = nLen; F6Q%<p a
} i!3*)-a\~`
catch(IOException e) sMUpkU-
{ yENAcsv
e.printStackTrace (); #8M^;4N>[
} h&d"|<
}0@@_Y]CC
%_B2/~
return n; gae=+@z
} U#iW1jPE2
p8YOow7)
ohJDu{V
} ,C0y3pL
!?+0O]`}
=OPX9oG
/* kv+^U^WoU
**SiteInfoBean.java gE=9K @
*/ k W 8>VnW
package NetFox; Fi;OZ>;a
0_+ & [g}
{+d)M
public class SiteInfoBean { Vmh$c*TE
' ;nG4+K
DS7L}]
private String sSiteURL; //Site's URL lVd-{m)
private String sFilePath; //Saved File's Path 8d Fqwpw8
private String sFileName; //Saved File's Name '!?t+L%gO
private int nSplitter; //Count of Splited Downloading File ,2 W=/,5A
&V+KM"Ow
A8ef=ljM?
public SiteInfoBean() +(afO~9
{//nSplitter的缺省值为5 % a.T@E
//default value of nSplitter is 5 E.ji;5
this("","","",5); K`<HZK
} wpi$-i`
GXQ%lQ
#G`K<%{?f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B>=D$*_
{ %, iAngF'
sSiteURL= sURL; O`GF|
sFilePath = sPath; P?n4B \!
sFileName = sName; xJU]py~o
this.nSplitter = nSpiltter; y0&vsoT
0rI/$
;bg]H >$U7
} wQd8/&mmk
4e AMb
&nI>`Q'
public String getSSiteURL() '@M"#`#0
{ $0un`&W
return sSiteURL; 8Lx1XbwK
} J` gG`?
mf{M-(6'
d6JW"
public void setSSiteURL(String value) rWDD$4y
{ aBG^Xhx
sSiteURL = value; ~x<?Pj
} X/vyb^:U
-@`Ah|m@}
$0 vT_
public String getSFilePath() P:vp/x!
{ <Z.{q Zd
return sFilePath; hwL`9.w
} u7RlxA:
2@ 9?~?r
e`LkCy[_
public void setSFilePath(String value) 'bSWJ/;p)
{ YVgH[-`,
sFilePath = value; L*,h=#x(
} K?!W9lUq
V]+y*b.60
DbFe;3
public String getSFileName() "!AtS
{ qGMU>J.;c
return sFileName; PLz+%L;{
} A[7H-1-
kp<Au)u
&S66M2
public void setSFileName(String value) +>*=~R
{ 4K7ved)
sFileName = value; \#Jq%nd
} x7<l*WQ
X`WS&!C<
eZ[Qhrc
public int getNSplitter() w@Q~ax/
{ <\Y(+?+uZ
return nSplitter; Et(H6O8
} B;NK\5>
z;?jKE p
O-W[^r2e
public void setNSplitter(int nCount) p!=8Pq.
{ [hg9 0Q6
nSplitter = nCount; W5Pur lu?
} ILH[q>
} lt:&lIW,3
fS|e{!iI"
^%Cd@!dk
/* o&@y^<UQ
**Utility.java XP}5i!}}7=
*/ @}!?}QU
package NetFox; uaKbqX
^b|? ?9&
GeB&S!F
public class Utility { Et-|[ eL
zZRLFfz<9
Viw,YkC
public Utility() 2~g-k3
{ iiJT%Zq`#
l$c/!V[3
1(# H%
} #`%S[)RT
P(8 uL|^
//线程睡眠 O_th/hl
public static void sleep(int nSecond) VbJE zl
{ S["r @<
try{ [kr-gV
Thread.sleep(nSecond); L1Yj9i
} <^{(?*
catch(Exception e) V62lN<M
{ sIaehe'B
e.printStackTrace (); ^*$!9~
} 1)ij*L8k
} G^K;+&T
30Qp:_D
//日志 f8r7SFwUv
public static void log(String sMsg) BSd.7W;cS=
{ 4A(h'(^7A
System.err.println(sMsg); 5-({z%:P
} y,`0f|
p}gA8o
T<Zi67QC@
public static void log(int sMsg) DyZ6&*s$
{ 9X33{
System.err.println(sMsg); f61vE
} wnXU=
} e F}KOOfC
3?_%|;ga
;KmrBNF
/* 7)RvBcM
**TestMethod.java "66#F
*/ |90/tNe
package NetFox; ".( G,TW
*u,&?fCl
M80O;0N%A
public class TestMethod { c3PA<q[
eIlovq/X
Uy)pEEu
public TestMethod() 2* TIr
{ ///xx/weblogic60b2_win.exe OBF-U]?Y
try{ ;Kg7}4`I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /f+BeQ3#/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pSYEC,0B
SiteFileFetch fileFetch = new SiteFileFetch(bean); #(+V&<K
fileFetch.start(); sP%b?6
} swJQwY
catch(Exception e){e.printStackTrace ();} p-DHTX
8.IenU9
Clap3E|a
} W*v3B.
C,LosAd
cb{"1z
public static void main(String[] args) -2 8bJ,
{ g\IwV+iDf
new TestMethod(); em- <V5fb
} ^/x\HGrw
} "*MF=VB1
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