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)); b@OL!?JP
} ("t; 2Mw
for(int i=0;i<nEndPos.length-1;i++) *3hqz<p4:
{ 3f`+-&|M
nEndPos = nStartPos[i+1]; UGy~Ecv
} vG'JMzAm
nEndPos[nEndPos.length-1] = nFileLength; <t{T]i+
} v'C`;I
} !O=J8;oLk
U!"+~d)
U$J l5[`F^
//启动子线程 9HOdtpQOV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $18|@\Znj
for(int i=0;i<nStartPos.length;i++) Q?GmSeUi
{ >Xq:?}-m2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "+js7U-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -f.<s!a
nStartPos,nEndPos,i); &#'[]V%^F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4#?OxvH
fileSplitterFetch.start(); p7Yej(B
} .[1"Med J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yfS`g-j{~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jXO*_R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q%=`PCty
nEndPos = " + nFileLength); 3A_7R-sQ
// fileSplitterFetch[nPos.length-1].start(); u-zl-?Ne
%3ecV$
8>TDrpT}
//等待子线程结束 R$@|t?
//int count = 0; X[:&p|g]
//是否结束while循环 $cri"G
boolean breakWhile = false; @Z.s:FV[
|IqQ%;H
+_gPZFpbx
while(!bStop) n&x#_B-
{ J9^RP~>bs
write_nPos(); tI&Z!fj
Utility.sleep(500); Oo<^~d2=
breakWhile = true; r"OVu~ND
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+I0?D
for(int i=0;i<nStartPos.length;i++) -r_/b
{ 3&!X8Lhv
if(!fileSplitterFetch.bDownOver) C,R_`%b%
{ Qo{Ez^q@J
breakWhile = false; Oslbt8)U6
break; C+-xC~
} 8$3G c"=
} {Slc6$
if(breakWhile) *<2+tI
break; vLW&/YJ6
jb8v3L
iIwMDlQ "
//count++; =<I90j~)
//if(count>4) :]Jwcp
// siteStop(); #$xiqL
} Exox&T
'vT XR_D
xX`P-h>V`c
System.err.println("文件下载结束！"); (eI'%1kS<
} N3Ub|$}q
catch(Exception e){e.printStackTrace ();} o'@VDGS`
} vV:eU-a
h Ns<Ae
mT;1KE{J{
//获得文件长度 T_:"~ ]
public long getFileSize() KTd,^h
{ yZbO{PMr
int nFileLength = -1; MoN;t;
try{ bZk7)b;1o
URL url = new URL(siteInfoBean.getSSiteURL()); RSG\3(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 89:Ys=
httpConnection.setRequestProperty("User-Agent","NetFox"); f5+a6s9
NaC^q*>9
hf rF7{yj
int responseCode=httpConnection.getResponseCode(); "gXz{$q
if(responseCode>=400) <4,>`#NEo
{ l|[cA}HtB
processErrorCode(responseCode); L2[|g~
return -2; //-2 represent access is error oJw~g[
} /"+n{*9
yzt6
|D u.aN
String sHeader; RQ#gn
+rbj%v}Fh
|?0Cm|?
for(int i=1;;i++) A,rgN;5fb
{ r*<)QP^B~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *4Cq,o`o>
//Utility.log(in.readLine()); q bb:)>
sHeader=httpConnection.getHeaderFieldKey(i); `/JJ\`Pu
if(sHeader!=null) zlIXia5
{ r'M|mQ$s>
if(sHeader.equals("Content-Length")) L)JpMf0
{ Fxy-_%a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k2l(!0o|;
break; Rm 1obP
} dhpEBJ
} C)/uX5
else Y[9x\6 _E
break; <#JJS}TLk
} a0OH
} Fku9hB
catch(IOException e){e.printStackTrace ();} &yv%"BPV
catch(Exception e){e.printStackTrace ();} ,/{mRw%
"|V{@)!t
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Utility.log(nFileLength); MjNCn&c
|U%S<X
q05_5
return nFileLength; oX@nWQBc_
} ufm`h)N
.P.TqT@)r
_|rrl
//保存下载信息（文件指针位置） 7yxZe4~|#
private void write_nPos() u&1n~t`
{ EAp6IhW{
try{ :\x53-&hO4
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;LNFPo
output.writeInt(nStartPos.length); nk9Kq\2f:
for(int i=0;i<nStartPos.length;i++) gUzCDB^.:
{ >up'`K,
// output.writeLong(nPos); pXPwn(
output.writeLong(fileSplitterFetch.nStartPos); A"FlH:Pn
output.writeLong(fileSplitterFetch.nEndPos); #bgW{&_y
} vULlAQG
output.close(); 48Y5ppcS
} "*|plB
catch(IOException e){e.printStackTrace ();} Z=n#XJO15
catch(Exception e){e.printStackTrace ();} 8=OK8UaU
} \^vf`-uG
pUki!TA
[R-4e; SRh
//读取保存的下载信息（文件指针位置） kVE% "
private void read_nPos() *IUw$|Z6z)
{ B)J.(k`p
try{ )vO;=%GQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cZT;VmC
int nCount = input.readInt(); ZvEcExA-
nStartPos = new long[nCount]; P|YBCH
nEndPos = new long[nCount]; z|[#6X6tT
for(int i=0;i<nStartPos.length;i++) Lzu;"#pw
{ I^sWf3'db
nStartPos = input.readLong(); YG$2ySkDhE
nEndPos = input.readLong(); Z W` Ur>
} 5*~Mv<#
input.close(); $8h^R#
} }C.M4{a\
catch(IOException e){e.printStackTrace ();} W@v@|D@
catch(Exception e){e.printStackTrace ();} 8WK%g0gm
} WJCEiH
)nU%}Z
Fv=7~6~
private void processErrorCode(int nErrorCode) q/~U[.C
{ SHS:>V
System.err.println("Error Code : " + nErrorCode); oB;EP
} L{(\k$>'
awN{F6@ZE
S]iMZ \I/
//停止文件下载 |9ro&KA
public void siteStop() YJ_`[LnL
{ DG}YQr.L
bStop = true; 4$J:A~2H]
for(int i=0;i<nStartPos.length;i++) ~(kIr?^
fileSplitterFetch.splitterStop(); YUd*\_
[vb>5EhL!
/*s:ehj
} L8n1p5gx3
} FDM&rQ
//负责部分文件的抓取 ZeD;
**FileSplitterFetch.java sL|lfc'bB
*/ "f\2/4EIl
package NetFox; BUB#\v#a
eSf e s
q/-8sO}q
import java.io.*; }7YDe'5V
import java.net.*; z:<mgp&/<
50% |9D0?Y
!U.Xb6
public class FileSplitterFetch extends Thread { =0 W`tx
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xxOo8+kA
String sURL; //File URL `"QUA G
long nStartPos; //File Snippet Start Position 9k=-8@G9
long nEndPos; //File Snippet End Position ;V]EF
int nThreadID; //Thread's ID bUbM}
boolean bDownOver = false; //Downing is over .CH0PK=l
boolean bStop = false; //Stop identical ;K38I}
FileAccessI fileAccessI = null; //File Access interface ;m$F~!Y
=t1.j=oC
4K`N3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3)v6N_
{ X||Z>w}v
this.sURL = sURL; OJ$169@;
this.nStartPos = nStart; X_|W#IM*+
this.nEndPos = nEnd; 6He7A@Eh
nThreadID = id; 2/S~l;x
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qp (ng8%c
} 0/P!rH9
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\ &1)k/
public void run() [z#C&gDt
{ F_;oZ
while(nStartPos < nEndPos && !bStop) "8|y
{ oZ95)'L,
7><ne|%
CK[2duf^~
try{ ) ?rJKr[`
URL url = new URL(sURL); d!/@+i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RbX!^v<0f6
httpConnection.setRequestProperty("User-Agent","NetFox"); .{ ^4I
String sProperty = "bytes="+nStartPos+"-"; S W(h%`U
httpConnection.setRequestProperty("RANGE",sProperty); 0-cqux2U
Utility.log(sProperty); KpBh@S
8;9GM^L
Knsb`1"E^6
InputStream input = httpConnection.getInputStream(); b9%}<w
//logResponseHead(httpConnection); Pm; /Ua
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qQN&uBQ[
byte[] b = new byte[1024]; eIc~J!?<&V
int nRead; {H s""/sb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dgPJte%i
{ ]4SnOSV?S
nStartPos += fileAccessI.write(b,0,nRead); e'aKI]>a
//if(nThreadID == 1) :0>wm@qCQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v<bq1QG
} `HU`=a&d
0z{S@
n m(yFX?=
Utility.log("Thread " + nThreadID + " is over!"); f"Yj'`6
bDownOver = true; j{N;2#.u
//nPos = fileAccessI.write (b,0,nRead); +:1ay^YI
} ~a m]G0
catch(Exception e){e.printStackTrace ();} )l*H$8
} }/BwFB+(/
} @OAX#iQl
0(#HMBE8
cAC2Xq
//打印回应的头信息 eU_|.2
public void logResponseHead(HttpURLConnection con) R-]QU`c
{ _H@s^g
for(int i=1;;i++) dj4 g
{ {;^booq
String header=con.getHeaderFieldKey(i); Us.yKAHPV
if(header!=null) `Yp\.K z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ERQa,h/
Utility.log(header+" : "+con.getHeaderField(header)); D4'"GaCv
else mtuq
break; 8,2l >S
} d}tn/Eu?B
} 9x.vz
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public void splitterStop() 8yax.N j
{ qT#+DDEAL
bStop = true; f|Kd{ $VO
} 65AXUTg
U,)Ngnd
_v4TyJ
} _=B(jJZ
xtf]U:c
XG<J'3
/* >JS\H6
**FileAccess.java {y<[1Pms
*//文件访问(定位，写) L5%~H?K(
package NetFox; >`= '~y8
import java.io.*; FOpOS?Cr'
w<j6ln+nM
VuFMjY
public class FileAccessI implements Serializable{ LfyycC2E
!;lA+O-t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >4GhI65
RandomAccessFile oSavedFile; 7>xxur&
long nPos; |DfYH~@(
,^O**k9F
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public FileAccessI() throws IOException Cca( oV
{ N J:]jd
this("",0); k#`.!yI,
} 7M}T^LC
(rFY8oHD
m}6GVQ'Q
public FileAccessI(String sName,long nPos) throws IOException rS/Q
{ }aXc,;Ps
oSavedFile = new RandomAccessFile(sName,"rw"); &9PzBc
this.nPos = nPos; xuO5|{h
oSavedFile.seek(nPos); N-jFA8n
} TJ7on.;
UY j
JI )+
public synchronized int write(byte[] b,int nStart,int nLen) 1Y@6oT
{ gj\r>~S
int n = -1; ~CldqXeI
try{ 2i', e
oSavedFile.write(b,nStart,nLen); #^<7VS!x
n = nLen; N::_JH?^=
} `y0ZFh1>X
catch(IOException e) 5ejdf
{ *gHOH!K,S
e.printStackTrace (); &PD4+%!
} IvetQ+
X55Eemg/
`j[)iok
return n; v"O{5LM"
} dGQxGt1
8^p/?R^bu
^SxB b,\
} N:0/8jmmO
nk1(/~`
9%oLv25{)
/* xBG&ZM4"^f
**SiteInfoBean.java r$;DA<<|<c
*/ .qy._C2(
package NetFox; w|>:mQnU
?A(=%c|,g
)HS|pS:
public class SiteInfoBean { wGd8q xa
`>rdn*B
RoM'+1nP:#
private String sSiteURL; //Site's URL Y {Klwn
private String sFilePath; //Saved File's Path + }(
private String sFileName; //Saved File's Name z|}Anc[\
private int nSplitter; //Count of Splited Downloading File eL^,-3JA(]
EU ThH.
=w".B[r
public SiteInfoBean() ~Ht[kO
{//nSplitter的缺省值为5 8l>/ZZ.NXi
//default value of nSplitter is 5 Cv{rd##Y8
this("","","",5); g Gg8O? Z
} %&Z!-k(
!rb)Y;WQt
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !-x^b.${B
{ VyCBJK
sSiteURL= sURL; .zlUN0oe
sFilePath = sPath; ; z:}OD
sFileName = sName; h_?D%b~5
this.nSplitter = nSpiltter; h\C
9g"a`a?c
-DX|[70
} Y!i4P#4+q
tAP~
Hh$D:ZO
public String getSSiteURL() |g> K$m^
{ [@#P3g\:>W
return sSiteURL; I6YN&9Y
} :b^tu8E
`"I^nD^t>Y
R2x(8k"LPU
public void setSSiteURL(String value) =B*,S#r
{ ;*wZgl
sSiteURL = value; 1P3^il7
} W: cOzJ
i4'?/UPc
.2!'6;K
public String getSFilePath() /V46:`V
{ cc.zC3Hs3
return sFilePath; m]=|%a6
} Z?G-~3]e
ocAoqjlT[
+_06{7@h
public void setSFilePath(String value) B2 Tp;)
{ 1A< O Z>
sFilePath = value; z]=A3!H/Y
} PS`v3|d}}}
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"%<Oadz ap
public String getSFileName() 6~&4>2b0f
{ d;:+Xd`
return sFileName; b0tr)>d
} ;-n+=@]7
mxq'A
KxGK`'E'r
public void setSFileName(String value) n_)d4d zl
{ -"\z|OQ
sFileName = value; Uj0DX>I
} 9FX'Uws
4ZQXYwfC|
P[8`]=
public int getNSplitter() _Wk!d3bsx
{ #`<|W5
return nSplitter; ;l &mA1+
} OY51~#BF
'd|_i6:y&
jv5p_v4%O
public void setNSplitter(int nCount) F,P,dc
{ +<Uc42i7n
nSplitter = nCount; .?[2,4F;
} ^B1Q";# B^
} +*DXzVC
}a'8lwF%I
W _yVVr
/* (VWTYG7
**Utility.java + 3aAL&
*/ 4rw<C07Z
package NetFox; ^WVH z;
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j Bl I^
public class Utility { zK}$W73W^
!HY+6!hk
1$q SbQ
public Utility() x a7x 2]~-
{ 06]J]
kRTT ~
Hp8)-eT
} SE;Jl[PgcL
Z[FSy-;"
//线程睡眠 kZ[E493bV
public static void sleep(int nSecond) v5;c}n
{ )<UNiC
try{ c9=;:E
Thread.sleep(nSecond); 7-'!XD!
} b9%hzD,MR
catch(Exception e) A>bo Xcr
{ UCa(3p^V_
e.printStackTrace (); mG1=8{o^
} bEMD2ABm
} mPi4.p)
R}#?A%,*
//日志 3(}W=oI
public static void log(String sMsg) `(q+@#)
{ z$QYl*F1
System.err.println(sMsg); TF^Rh4
} # yAt `
MkRRBvk
f}Mc2PQ-
public static void log(int sMsg) {qp XzxV
{ "/S-+Ufn
System.err.println(sMsg); 2pQ zT
} 38tRb"3zP
} dK#:io[Nz
lN<vu#
TXv3@/>ZlG
/* E"b+Q
**TestMethod.java 0%<Fc9#
*/ ^}a..@|%W
package NetFox; jri=UGf
gH,^XZe
P@`@?kMU
public class TestMethod { 3T'9_v[Y
VWj]X7v
?rKewdGY
public TestMethod() ,j:`yB]4,
{ ///xx/weblogic60b2_win.exe 0/6f9A
try{ yrSmI)&%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q=)$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fk<0~tE
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9G[!"eZ}
fileFetch.start(); U6t>UE6k
} {dH87 nt
catch(Exception e){e.printStackTrace ();} (OLjE]9;
J2f}{!b+I
9f\Lon4lX
} etMQy6E\
'P0:1">
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public static void main(String[] args) mp*&{[XoVC
{ Q_$aiE
new TestMethod(); ]o$aGrZ
} }Y[xj{2$O
} TTZb.
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