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)); rJg!2
} &z,w0FOre
for(int i=0;i<nEndPos.length-1;i++) fe&K2C%bm
{ lRentNg0b
nEndPos = nStartPos[i+1]; Kh%9Oy
} tAaFIIvY
nEndPos[nEndPos.length-1] = nFileLength; 1UmV&
} o&X!75^G>
} 9i9VDk{
D^f;dT;-
k^ID
//启动子线程 3+(Fq5I
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sLB{R#Pt
for(int i=0;i<nStartPos.length;i++) ;pC-0m0Y
{ P$w0.XZa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7';PI!$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Jzfzy0$
nStartPos,nEndPos,i); &)`A4bf%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3Vt-]DGX
fileSplitterFetch.start(); ?hmj0i;XC
} A$%%;O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Grkj@Q*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b-~Gt]%>m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8$@gAlI^
nEndPos = " + nFileLength); {{giSW'
// fileSplitterFetch[nPos.length-1].start(); Imi_}NB+
N{E>R&,q
{?#g*QF|^
//等待子线程结束 .F> cZ,
//int count = 0; fr:RiOPn
//是否结束while循环 8=<d2u'
boolean breakWhile = false; t7R;RF
P\w.:.2
jJg 'Y:K9q
while(!bStop) HnU}Lhjzj
{ |-2,k#|
write_nPos(); l|\Q~ D!o
Utility.sleep(500); ^<ayPV)+
breakWhile = true; kOJs;k
[UFLL:_sC
fMhMB |W.
for(int i=0;i<nStartPos.length;i++) @hg1&pfxZ<
{ Elm/T]6
if(!fileSplitterFetch.bDownOver) pdmeB
{ L?0dZY-"
breakWhile = false; +D$\^ <#
break; ^[d)Hk}L
} .GkH^9THP
} xS*f{5Hr8
if(breakWhile) Ugrcy7
break; Z7OWpujCvN
5C2 *f4|
J[]YG+r
//count++; .Ml}cE$L
//if(count>4) Wh 8fC(BE
// siteStop(); eWcS>N
} e7 5*84
"y>l2V,4j%
-/KVZ
System.err.println("文件下载结束！"); Fi1gM}>py
} "(T@*"vX2
catch(Exception e){e.printStackTrace ();} ;M\H#%G.
} WG(tt.
U%j=)VD])
O"_FfwO a
//获得文件长度 ~#@sZ0/<
public long getFileSize() \ $z.x-U
{ 3Pkzzyk_|D
int nFileLength = -1; IjJ3./L!5
try{ QT^W00h
URL url = new URL(siteInfoBean.getSSiteURL()); xZbm,.v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \q%li)
httpConnection.setRequestProperty("User-Agent","NetFox"); H@5:x8
)2u=U9
QvjsI;CQ-
int responseCode=httpConnection.getResponseCode(); U0UOubA
if(responseCode>=400) =f=MtH?0y
{ 9C3q4.$D
processErrorCode(responseCode); +7d%)t
return -2; //-2 represent access is error |.)dOk,o
} f; >DM
7S1 Y)
9cX ~
String sHeader; @yS
r|6S&Ia>
zVJwmp^
for(int i=1;;i++) !<@k\~9^D
{ 4AzS~5S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WE68a!6
//Utility.log(in.readLine()); ~vBmW_j
sHeader=httpConnection.getHeaderFieldKey(i); *W%HTt"N
if(sHeader!=null) i wQ'=M
{ vvFXdHP
if(sHeader.equals("Content-Length")) }3 RqaIY}
{ 3($%AGKJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }4 5|
break; #Ubzh`v
} O0';j!?X
} _`*x}
else >jRz4%
break; kbBX\*{yh
} ``$At,m
} vw>O;u.]B
catch(IOException e){e.printStackTrace ();} OGrp{s
catch(Exception e){e.printStackTrace ();} D8C@x`
n3jA[p:
UYD(++
Utility.log(nFileLength); )9{?C4NQ
=-1d m+P
Ojr{z
return nFileLength; K{t7_i#tv
} %AXa(C\1
$ZH$x3;
Iy6"2$%a
//保存下载信息（文件指针位置） ?_(0cVi
private void write_nPos() #rF|X6P
{ rhHX0+
try{ #/MUiV
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8s6[?=nM
output.writeInt(nStartPos.length); o_vK4%y(
for(int i=0;i<nStartPos.length;i++) srw5&s(3X
{ <dLdSEw
// output.writeLong(nPos); M g1E1kXe
output.writeLong(fileSplitterFetch.nStartPos); u&mB;:&
output.writeLong(fileSplitterFetch.nEndPos); `.>2h}op
} E<>n0",
output.close(); (Lo<3a-]
} i/NY86A
catch(IOException e){e.printStackTrace ();} ;vc$;54K
catch(Exception e){e.printStackTrace ();} 4%aODr8
} ? D2:'gg
2_ <
B=JeZMn
//读取保存的下载信息（文件指针位置） `7LN?- T
private void read_nPos() 4?jXbC k~x
{ r8pTtf#Q
try{ ?9i 7w1`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qXn%c"
int nCount = input.readInt(); M%/ML=eLi
nStartPos = new long[nCount]; m%X~EwFc.
nEndPos = new long[nCount]; v1 d]
for(int i=0;i<nStartPos.length;i++) TGY^,H>J
{ ]Z&2
nStartPos = input.readLong(); O|O#T.Tg
nEndPos = input.readLong(); [Z`q7ddd^
} +D&W!m
input.close(); EXK~Zf|&Z
} 1X.5cl?V
catch(IOException e){e.printStackTrace ();} &D\~-fOGb
catch(Exception e){e.printStackTrace ();} <2HI. @^
} cP`o?:
&$ia#j{l
C6Ap 4
private void processErrorCode(int nErrorCode) jt@k<#h~
{ gxycw4kz
System.err.println("Error Code : " + nErrorCode); 5#!pwjt~7
} -e3m!h
ygW,4Vz7J
Mmq{]q~At
//停止文件下载 B- N
public void siteStop() Ia*eb%HG
{ 8B"jvrs
bStop = true; g|a2z_R
for(int i=0;i<nStartPos.length;i++) sF:3|Yy0
fileSplitterFetch.splitterStop(); aF1pq
Wo<zvut8
jFZJ #'CNS
} rQC{"hS1
} -5l74f!i
//负责部分文件的抓取 v<,?%(g)7
**FileSplitterFetch.java qY]IX9'kV
*/ 'QFf 7A
package NetFox; ,9^wKS!7$
Y.Na9&-(
n{J<7I e"*
import java.io.*; '-p<E"#4Z
import java.net.*; ]O3[Te
~9#\+[ d_
X!2/cgU7
public class FileSplitterFetch extends Thread { CaX&T2(
=P\H}?PF
;,}tXz
String sURL; //File URL J GnL[9P_
long nStartPos; //File Snippet Start Position n a])bBn
long nEndPos; //File Snippet End Position -8X*(7
int nThreadID; //Thread's ID \/*r45!
boolean bDownOver = false; //Downing is over ,YX[6eZr
boolean bStop = false; //Stop identical N93 ZI|T
FileAccessI fileAccessI = null; //File Access interface kep.+t[
~v$gk
Z#IRNFj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8 C@iD%
{ x3xBl_t
this.sURL = sURL; s de|t
this.nStartPos = nStart; 9]r6V
this.nEndPos = nEnd; ZMQSy7
nThreadID = id; DJr{;t$7~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {wiw]@c8
} !U>711$
v?F~fRH
6H\3
public void run() .-T^S"`d|
{ LSv0zAIe/
while(nStartPos < nEndPos && !bStop) 0&E{[~Pv
{ Jb Hn/$
\b?z\bC56
"yxIaTZu
try{ @jAuSBy
URL url = new URL(sURL); 3#}5dO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?u{y[pI6
httpConnection.setRequestProperty("User-Agent","NetFox"); ~,Ck
String sProperty = "bytes="+nStartPos+"-"; Ho9 a#9
httpConnection.setRequestProperty("RANGE",sProperty); /xj^TyWM
Utility.log(sProperty); SsiAyQ|Ma
Z6\OkD
c&z@HEzV7
InputStream input = httpConnection.getInputStream(); vG`R.
//logResponseHead(httpConnection); eL[BH8l
h lD0^8S
7Rqjf6kX`O
byte[] b = new byte[1024]; s|.V:%9e
int nRead; N1`/~Gi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H]K(`)y}4
{ )<-\ F%&b
nStartPos += fileAccessI.write(b,0,nRead); k;/U6,LQ*
//if(nThreadID == 1) @JVax-N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6 6WAD$8$
} Ll\y2oJ
U@yn%k9
[GJ_]w^}j
Utility.log("Thread " + nThreadID + " is over!"); #)QR^ss)iw
bDownOver = true; vzA)pB~;
//nPos = fileAccessI.write (b,0,nRead); Dp4\rps
} %GQPiWu
catch(Exception e){e.printStackTrace ();} nm2bBX,fh
} m~mw1r
} ,r!_4|\
$e1==@ R
@eu4W^W
//打印回应的头信息 6a51bj!f
public void logResponseHead(HttpURLConnection con) |{udd~oE&
{ Elw fqfO
for(int i=1;;i++) GawQ~rD
{ tP8>0\$)
String header=con.getHeaderFieldKey(i); CqOvVv
if(header!=null) 0+p <Jc!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `Nmw
Utility.log(header+" : "+con.getHeaderField(header)); H5j6$y|I|N
else E Mq P
break; Li)rs<IX;m
} o<Hk/e~
} w}nc^6qH
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#lXwBfBMf
public void splitterStop() :23w[vt=
{ ;DbEP.%u$
bStop = true; xwoK#eC~F
} ( `T;nz
#m[R1G#
s>hNwb/
} PoTJ4z
6wK>SW)#&j
g93-2k,
/* ;G_{$)P.o
**FileAccess.java CR3<9=Lv>
*//文件访问(定位，写) YQGVQ[P
package NetFox; I~ Q2jg2
import java.io.*; ?T]3I.3 2^
?Co)7}N
;cKN5#7
public class FileAccessI implements Serializable{ R"%zmA@o=
NH+?7rf8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L|O[u^
RandomAccessFile oSavedFile; x{y}pH"H
long nPos; }Fs;sfH
EY'kIVk
lr[U6CJY
public FileAccessI() throws IOException 2H+!78
{ x-J.*X/aB
this("",0); !0i6:2nw
} t&m8 V$Q
3[`/rg,
Yl}'hRp
public FileAccessI(String sName,long nPos) throws IOException mN+ w,
{ Uj]Tdg
oSavedFile = new RandomAccessFile(sName,"rw"); 5qZebD2a
this.nPos = nPos; zl8O @g
oSavedFile.seek(nPos); lsJl+%&8
} 2Iv&XxSo
vKrOIBP
K[{hh;7
public synchronized int write(byte[] b,int nStart,int nLen) dQW=k^X 'U
{ |qe[`x; %
int n = -1; G':wJ7[]`
try{ lRb|GS.h/
oSavedFile.write(b,nStart,nLen); v0psth?qV
n = nLen; $aIq>vJO9
} c:? tn
catch(IOException e) BJA&{DMHm
{ [{R^!Az&b<
e.printStackTrace (); *nZe|)m
} Wgp}v93
\piB*"ln
<K6gzi0fl
return n; Jkf%k3H3I*
} LdAWCBLS
:@x_& b
\_GG6
} :'hc&wk`
7I\qEr57
{nQ?+o3
/* 2H\}N^;f
**SiteInfoBean.java 8kn> ?
*/ aL?+# j^"
package NetFox; K9z 1'k QH
6b!F7kyg
LsW7JIQd
public class SiteInfoBean { M{(g"ha
]Q8[,HTG
(}!xO?NA(
private String sSiteURL; //Site's URL [Q0n-b,Q
private String sFilePath; //Saved File's Path Ui:WbH<b{
private String sFileName; //Saved File's Name 7dxe03h
private int nSplitter; //Count of Splited Downloading File ohLM9mc9
,#/%Fn%T
)-jA4!&
public SiteInfoBean() >oD,wSYV~
{//nSplitter的缺省值为5 10gh4,z[
//default value of nSplitter is 5 X%>nvp
this("","","",5); -q&K9ZCl`
} r^g"%nq9/
9K4]~_%h\
x`3F?[#l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?ZF~U
{ {e35O(Y
sSiteURL= sURL; \}Hi\k+h':
sFilePath = sPath; >_3P6-L>
sFileName = sName; FGRdA^`
this.nSplitter = nSpiltter; P]A~:Lj
+Oxw?`I$
0gevn
} '?gF9:
PH1jN?OEwZ
>IT19(J;A
public String getSSiteURL() tZL|;K
{ s@$SM,tnn
return sSiteURL; 6x*$/1'M3;
} 59R%g .2Y
;:WM^S
uge~*S
public void setSSiteURL(String value) yhPO$L
{ xGkc_
sSiteURL = value; 6d;_}
} L>3-z>u,
#qnK nxD
/l%+l@
public String getSFilePath() w/49O;rV
{ m=K46i+NE
return sFilePath; vB?(|
} [gkOwU=?
Zws[C
|a|##/
public void setSFilePath(String value) S Boi|
{ 0F5QAR O
sFilePath = value; a#pM9n~a
} -J& b~t@
W Te1E,M
lj US-6
public String getSFileName() )x<oRHx]
{ )k~{p;Ke
return sFileName; 1m{c8Z.h/d
} dq4t@:\o0
6uu49x_^L4
^1\[hyZ!
public void setSFileName(String value) hpBn_
{ A+QOox]<
sFileName = value; Io*mFa?
} ~a ]R7X7
}Q1m
Fs_zNN
public int getNSplitter() qKjUp"
{ aYmN' POi
return nSplitter; )e?6 Ncy
} Y$4dqn
X[E!q$ag
m\"X%Y#
public void setNSplitter(int nCount) ?l?_8y/ww
{ 4_KRH1
nSplitter = nCount; FdE9k\E#/)
} d%lwg~@&|5
} m`!Vryf
D>6vI
s~b!3l`gu
/* @|;XDO`k;
**Utility.java rx\f:-3g
*/ '{F Od_uk%
package NetFox; VthM`~3
PBY;SG~
SrT=XX,
public class Utility { 6xW17P
KkPr08
`]$H\gNI[8
public Utility() ,AuejMd
{ /8[T2Z!
xN>+!&3%w
FNHJHuTe
} _OY<Hb3%M
BnPL>11Y
//线程睡眠 T,uVt^.R+
public static void sleep(int nSecond) IuOQX}
{ FV>xAU$
try{ IWNIk9T,u
Thread.sleep(nSecond); 'Im&&uSkr
} Epm%/ {sHV
catch(Exception e) &B@qb?UE1
{ W:y'a3~
e.printStackTrace (); wpepi8w,
} $E35W=~)
} ;Ebpf J
,&aD U
//日志 VCCG_K9'
public static void log(String sMsg) yiAusl;
{ lFc4| _c g
System.err.println(sMsg); z\6/?5D#v
} k}908%w
0$I!\y\
mF@DO$
public static void log(int sMsg) B[{Ie G'
{ ;o?Wn=J
System.err.println(sMsg); l EsE]f
} I%# e\
} n,o;:c
idGhWV'
F^}n7h=qk
/* od`:w[2\
**TestMethod.java Xb5$ijH
*/ ;h#nal>w@S
package NetFox; I.L8A|nZ
}ej-Lu,b3
*+>R^\uT
public class TestMethod { xOXCCf/
Fwfe5`9'
+Heen3
public TestMethod() ^ ^R4%C
{ ///xx/weblogic60b2_win.exe K0\Wty0
try{ o](nK5?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i \u"+:j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^`Qh*:T$
SiteFileFetch fileFetch = new SiteFileFetch(bean); &xjeZh4-
fileFetch.start(); &Vi0.o
} sAKQ.8$h*
catch(Exception e){e.printStackTrace ();} }hX"A!0
t.tdY
"Qxn}$6-
} :O{oVR
aShZdeC*f
i4*!t.eI
public static void main(String[] args) 4j h4XdH
{ m8ydX6~max
new TestMethod(); lITZ|u
} ]Zz<9zix
} *|Fl&`2
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