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)); X!z-J>
} pwHe&7e#
for(int i=0;i<nEndPos.length-1;i++) 4>L*7i
{ #M w70@6
nEndPos = nStartPos[i+1]; x{w|Hy
} ) aMiT
nEndPos[nEndPos.length-1] = nFileLength; {RI^zNgs[
} -;"A\2_y
} N@<-R<s^
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Il@K8?H@
//启动子线程 x@oxIXN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7#UJ444b~
for(int i=0;i<nStartPos.length;i++) C "@>NC_
{ RZpjr !R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xE--)=<$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KV;q}EyG
nStartPos,nEndPos,i); _IU5HT}2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6j{ynt
fileSplitterFetch.start(); 85|u;Fxf
} K-Pcew^?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1qn/*9W}=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R1Rk00Ow:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _/P;`@
nEndPos = " + nFileLength); "\;n t5L
// fileSplitterFetch[nPos.length-1].start(); =m (u=|N3
0k\,z(e
kP('X/
//等待子线程结束 M+ <SSi"
//int count = 0; `:r-&QdU o
//是否结束while循环 .e3@fq
boolean breakWhile = false; '*`n"cC:
.,S`VNU
j&S.k
while(!bStop) 16I[z+RG
{ yG~Vvpv
write_nPos(); X[<#B5
Utility.sleep(500); J#@+1 Nt
breakWhile = true; 8#A4B2
\A\?7#9\
d<OdQvW.
for(int i=0;i<nStartPos.length;i++) qu$FpOJ
{ aG =6(ec.
if(!fileSplitterFetch.bDownOver) "Zn nb*pOM
{ .%W.uF^
breakWhile = false; 45%D^~2~F
break; M"K$.m@t
} d<=!*#q;o
} /03Wst
if(breakWhile) DU*qhW`X
break; PK&&Vu2M
yF|yZ{
2'W#x
//count++; q%A>q;l:
//if(count>4) UL~~J[1r
// siteStop(); HXdo:#xEO
} tNZZCdB
<Mo{o2F=
UHfE.mTjM
System.err.println("文件下载结束！"); G;/> N'#
} +[ir7?Y.
catch(Exception e){e.printStackTrace ();} l>i:M#z&
} 8?<J,zu@AV
&dw=jHt
c@]G;>o
//获得文件长度 ca0vN^Ji
public long getFileSize() ^a3 (QKS
{ r_bG+iw7p
int nFileLength = -1; 7bGt'gvv
try{ bqF?!t<B
URL url = new URL(siteInfoBean.getSSiteURL()); 4C:dkaDq]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OOnj(%g
httpConnection.setRequestProperty("User-Agent","NetFox"); t^6ams$
cyjgi /Z
# E8?2]
int responseCode=httpConnection.getResponseCode(); +W-b3R:1>
if(responseCode>=400) Ty!V)i
{ J- l[dC
processErrorCode(responseCode); 2.{<C.BK{
return -2; //-2 represent access is error P$ b5o
} fyx Q{J
NX;{L#lQ
BjjuZN&
String sHeader; w}07u5
Ut1s~b1
}p)a7xn}
for(int i=1;;i++) yVPFH~1@\
{ Bv*VNfUm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %%wngiz\
//Utility.log(in.readLine()); nddCp~NX
sHeader=httpConnection.getHeaderFieldKey(i); ecvZwL
if(sHeader!=null) 9/&1lFKJ
{ 0f+]I=1\
if(sHeader.equals("Content-Length")) 0U.Ld:
{ @JP6F[d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #=m:>Q?%z
break; %A&g-4(
} NLgeBLB
} > -fXn
else lY[1P|]
break; McdK!V
} ]8cD,NS
} F?y C=
catch(IOException e){e.printStackTrace ();} r|3u]rt
catch(Exception e){e.printStackTrace ();} ZiH4s|
bhZ5-wo4%
DAMw(
Utility.log(nFileLength); geqx":gpx9
`I|Y7GoUO
cIuCuh0I`
return nFileLength; * _,yK-et
} dftX$TS
73nmDZO|
6p,}?6^
//保存下载信息（文件指针位置） ~ :B/`1[m
private void write_nPos() 0R&7vn
{ 3`"k1W
try{ ]<fZW"W<q
output = new DataOutputStream(new FileOutputStream(tmpFile)); }4Gn$'e
output.writeInt(nStartPos.length); R3BK\kf&
for(int i=0;i<nStartPos.length;i++) hH?ke(&=f
{ ) I.uqG
// output.writeLong(nPos); -fK_F6_\]
output.writeLong(fileSplitterFetch.nStartPos); diw5h};W
output.writeLong(fileSplitterFetch.nEndPos); GL&rT&
} p1ER<_fp
output.close(); kY~yA2*G
} L{c\7
catch(IOException e){e.printStackTrace ();} TjctK [db@
catch(Exception e){e.printStackTrace ();} KZ [:o,jp>
} }L5;=A']S
MF::At[4
k@9q5lu;T
//读取保存的下载信息（文件指针位置） 2+LvlS)C
private void read_nPos() U4e9[=q`'
{ z-S8s2.Fd
try{ 7H[.o~\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6SSrkj}U
int nCount = input.readInt(); # kmI#W"^
nStartPos = new long[nCount]; 6<n+p'+n
nEndPos = new long[nCount]; ia-&?
for(int i=0;i<nStartPos.length;i++) DsiyN:o'+
{ lWU? R
nStartPos = input.readLong(); &G+:t)|S
nEndPos = input.readLong(); 2|+4xqNJm
} kr]_?B(r
input.close(); 3SOrM
} .noY[P8i
catch(IOException e){e.printStackTrace ();} )q%DRLD'G
catch(Exception e){e.printStackTrace ();} 9Bu=8P?
} UWBR5
).HnK
a'\fS7aE0l
private void processErrorCode(int nErrorCode) 8 A#\V
{ .lppT)P
System.err.println("Error Code : " + nErrorCode); !AL?bW
} ]G=^7O]`C!
A^ry|4`3(
B|BJkY'
//停止文件下载 MCfDR#a
public void siteStop() N8]d0
{ Y{m1\s/o
bStop = true; rP&.`m88n
for(int i=0;i<nStartPos.length;i++) N5fMMi(O
fileSplitterFetch.splitterStop(); (Yc}V
`q1K%id
mY]R~:
} DzvGR)>/
} n11eJEtm
//负责部分文件的抓取 9uY$@7qH
**FileSplitterFetch.java 2`h
*/ %XWb|-=
package NetFox; zeHs5P8}r
XE*#5u8t
sX=_|<[
import java.io.*; lem\P_V)
import java.net.*; WAh{*$Rpl
*s"{JrG`O
"V7&@3
public class FileSplitterFetch extends Thread { as@I0e((
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String sURL; //File URL ~FZ=
long nStartPos; //File Snippet Start Position '\Hh
long nEndPos; //File Snippet End Position l,M?
int nThreadID; //Thread's ID kR(hUc1O
boolean bDownOver = false; //Downing is over Y!nE65
boolean bStop = false; //Stop identical KZTT2KsYl
FileAccessI fileAccessI = null; //File Access interface SNf*2~uq)
x-s]3'!L
Y-:{a1/RKo
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sBu- \P#
{ A!!W\Jt
this.sURL = sURL; yi3Cd@t({{
this.nStartPos = nStart; h{M.+I$}C
this.nEndPos = nEnd; e?!A]2
nThreadID = id; 9.$k^|~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1'[_J
} tdB<
. [\S=K|/
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public void run() pWXoJ0N
{ *H%Jgz,
while(nStartPos < nEndPos && !bStop) C)`y<O
{ elm]e2)F
+}0/ %5 =1
D[ (A`!)
try{ a-7T
URL url = new URL(sURL); JN-wToOF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }zu?SZH
httpConnection.setRequestProperty("User-Agent","NetFox"); 72>/@
String sProperty = "bytes="+nStartPos+"-"; 3]}wZY0
httpConnection.setRequestProperty("RANGE",sProperty); } ^67HtNQ
Utility.log(sProperty); Vi1= E])
o72G oUfs
\"@BZ.y
InputStream input = httpConnection.getInputStream(); ril4*$e7^\
//logResponseHead(httpConnection); !r*Ogv[
\sZ!F&a~
ACcxQK}
byte[] b = new byte[1024]; V/}g'_E
int nRead; z<c@<M=Q*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fB3W} dr
{ !4B($]t
nStartPos += fileAccessI.write(b,0,nRead); !B &%!06
//if(nThreadID == 1) B'Ll\<mq@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); + \AiUY
} }?jL;CCe
@NS=
kG>d^K
Utility.log("Thread " + nThreadID + " is over!"); ^ LTKX`p
bDownOver = true; \-B8`ah
//nPos = fileAccessI.write (b,0,nRead); J2W:Q
} R4Vi*H
catch(Exception e){e.printStackTrace ();} {m/h3hjFa
} ]N+(SU
} A\7qPfpG
LD~/*
Eh&et0&=g
//打印回应的头信息 jKI0d+U
public void logResponseHead(HttpURLConnection con) 6Tn.56X
{ ~]_gq;bG
for(int i=1;;i++) d)&}% 2ku
{ D> |R.{
String header=con.getHeaderFieldKey(i); ' s6SKjZS
if(header!=null) 7C%z0/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4iiW{rh4
Utility.log(header+" : "+con.getHeaderField(header)); Z;6v`;[
else <g|\]\C|
break; 2}P?N
} L`Lro:E?kL
} OTNcNY
1\_S1ZS
5P'<X p
public void splitterStop() ~a^"VQ5]ac
{ U!rhj&n
bStop = true; ,s*-2Sz
} WZa?Xb
&xG>"sJ
wua`e <"
} dd +%d
+&7D ;wj=
"r Bb2.
/* XUrxnJ4
**FileAccess.java qMrBTq[
*//文件访问(定位，写) '7UW\KEB[}
package NetFox; yrnIQu*Uu
import java.io.*; %,G&By&,
$s*\yam?|
%4/>7 aB]Y
public class FileAccessI implements Serializable{ Vnu*+
zYpIG8"o5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q>7#</i\.
RandomAccessFile oSavedFile; ac>}$Uw)
long nPos; D *W+0
8~RUYsg
_Ptf^+
public FileAccessI() throws IOException fC xN!
{ +5Ir=]=T9
this("",0); -aG( Yx
} XOa<R
Noz+\O\
j{VxB
public FileAccessI(String sName,long nPos) throws IOException *7oPM5J|v
{ 0K>rc1dy
oSavedFile = new RandomAccessFile(sName,"rw"); RL~|Kr<7J
this.nPos = nPos; C yC<{D+
oSavedFile.seek(nPos); g_;5"
} ~B>I?j
Z]$yuM
1jo.d
public synchronized int write(byte[] b,int nStart,int nLen) O8SX#,3^}
{ 8"wA8l.
int n = -1; NrVQK}%K
try{ N\H{p%8
oSavedFile.write(b,nStart,nLen); ./kmI#gaV
n = nLen; v3S{dX<
} Bx E1Ky8@A
catch(IOException e) r&}fn"H!
{ T7m rOp
e.printStackTrace (); b9EJLD
} gb@Rx
W~W^$A
\ :})R{
return n; $>/J8iB
} z-[Jbjhd
|:!#kA
tRbZ^5x\@
} 0J$wX yh
zQ]IlMt
)~d2`1zGS
/* BOL_kp"
**SiteInfoBean.java a6WE,4T9
*/ "4g1I<
package NetFox; t8GJ;
dq:M!F
kGc)Un?'{U
public class SiteInfoBean { }C"#b\A2
>ID 3oi
H/)=
private String sSiteURL; //Site's URL DX$`\PA
private String sFilePath; //Saved File's Path [n74&EH
private String sFileName; //Saved File's Name KN}[N+V>
private int nSplitter; //Count of Splited Downloading File y H+CyL\
GmAE!+"
J)jiI>
public SiteInfoBean() NPB':r-8
{//nSplitter的缺省值为5 ^D.B^BR
//default value of nSplitter is 5 Y%=A>~s*c:
this("","","",5); uT-WQ/id
} <V6#)^Or
gLpWfT29V
ew`R=<mZ,7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @ K@~4!
{ <NJ7mR}
sSiteURL= sURL; N_gjOE`x5
sFilePath = sPath; nosEo?{
sFileName = sName; dk(-yv'
this.nSplitter = nSpiltter; ?: meix
TfZO0GL$
|LNXu
} }kOhwT8sI
(|6qN
*=2jteG=3.
public String getSSiteURL() fA3
{ b-O4IDIT
return sSiteURL; /(}V!0\?
} "lz!'~im
O'wN4qb=F
Q?Nzt;)!.
public void setSSiteURL(String value) qp{NRNkQ
{ J,~)9Kh$
sSiteURL = value; n]o+KT\
} 9J|YP}%
"3^6
g{D&|qWj
public String getSFilePath() n `n3[
{ "RShsJZMH
return sFilePath; \JyWKET::_
} #qn)Nq(
u>(Q& 25
A>4k4*aFm#
public void setSFilePath(String value) L,D!T&B
{ ebao7r5@
sFilePath = value; -p;oe}|
} HOUyB's'
&U,f~KJ
2fLd/x~
public String getSFileName() rxz3Mqg
{ lGM3?AN
return sFileName; KC]Jbm{y
} hZ#tB
H\b5]q%
&t8_J3?Z
public void setSFileName(String value) $yc,D=*Isi
{ s<dD>SU
sFileName = value; Z8#I
} 9D| FqU |
2$Ji4`p}S
q+:(@w6
public int getNSplitter() lt$797
{ i&30n#
return nSplitter; U-? ^B*<
} g:6yvEu$ -
m0* B[
zo5.}mr+
public void setNSplitter(int nCount) N1Z8I:
{ N4v)0
nSplitter = nCount; X@Bpjg
} UxvsSHi
} c@^:tB
rzmk-V
6nfkZvn
/* xh6x B|Z
**Utility.java _l,Z38
*/ I>3]4mI*a
package NetFox; 2%qn!+.
PHK#b.B>a8
:fYwFD( 9
public class Utility { _]S6>
p)^:~ll
`p{!5
public Utility() Yz,!#ob$
{ w.Vynb
)ra66E
xI4I1"/
} D+)=bPMe
Riw7<j
//线程睡眠 ],YYFU}
public static void sleep(int nSecond) -h@0 1
{ 1a$V{Eag
try{ DqMK[N,0
Thread.sleep(nSecond); BXo|CITso
} Doh|G:P]#
catch(Exception e) ^!<7#kX
{ z;C=d(|nN
e.printStackTrace (); 1(i>Vt.+
} W#L"5pRg
} J=X% xb
MH.,s@
//日志 =b!J)]
public static void log(String sMsg) .G_3blE;
{ GeaDaYh#T
System.err.println(sMsg); mrC+J*
} )6Q0f
~{vdP=/WP
gww^?j#
public static void log(int sMsg) K)`:v|d
{ ZGpTw[5ql
System.err.println(sMsg); #a |ch6B
} 5g1M_8e'+
} v$m[#&O^V?
aoDD&JE
PGPbpl&\t
/* o~x39
**TestMethod.java ;(Xe@OtW
*/ Yb\\ w<@g
package NetFox; uUz`=4%A
+qUkMx
pTALhj#,
public class TestMethod { T5azYdzJy
!wd'::C
hO/5>Zv?
public TestMethod() XU_,Z/Yw_
{ ///xx/weblogic60b2_win.exe #t@x6Vt
try{ f5aF6FBH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #<wpSs
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tP`G]BCbt
SiteFileFetch fileFetch = new SiteFileFetch(bean); !(*a+ur&i
fileFetch.start(); rMHQzQ0%
} }xb_s
catch(Exception e){e.printStackTrace ();} < m enABN4
OwA~(
V5O=iMP
} )[^y t0%
;tp]^iB#
m-ph}
public static void main(String[] args) nuSN)}b<Q
{ JOrELrMx
new TestMethod(); #Pu@Wx
} rX33s
} F#1 Kk#t
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