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)); jOfG}:>e\
} 6ncwa<q5
for(int i=0;i<nEndPos.length-1;i++) P'8RaO&d
{ A^z{n/DiL
nEndPos = nStartPos[i+1]; iUcX\ uW
} ~4~r
nEndPos[nEndPos.length-1] = nFileLength; iG54 +]
} KUU{X~w
} b+qd' ,.Z
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s_y8+BJaV
//启动子线程 nIg 88*6b,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +w]#26`d
for(int i=0;i<nStartPos.length;i++) Cik1~5iF
{ X,w X)9]J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L/ibnGhq]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [>v1JN
nStartPos,nEndPos,i); Cqnuf5e>L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yq;[1O_9C
fileSplitterFetch.start(); 1=J& ^O{W
} e7GYz7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?:$ q~[LY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4x)vy-y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PI*@.kqR-
nEndPos = " + nFileLength); 5/nL[4Z
// fileSplitterFetch[nPos.length-1].start(); 2ul8]=
&6s&nx
)$S=iL8(
//等待子线程结束 -6DRX
//int count = 0; C1NU6iV^z
//是否结束while循环 U2YY
boolean breakWhile = false; tsg`c;{
=OFhM7
Q$5t~*$`
while(!bStop) 4\-11!'08
{ =?C <@
write_nPos(); k( 0;>)<i
Utility.sleep(500); eAW)|=2
breakWhile = true; :^kAFLU
a,oTU\m C
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for(int i=0;i<nStartPos.length;i++) vU%K%-yXG7
{ ;w.la
if(!fileSplitterFetch.bDownOver) #@DJf
{ TQck$&
breakWhile = false; !nl-}P,
break; 9 3)fC
} ^Saf z8-3o
} 2*75*EQCH
if(breakWhile) *>W<n1r@]
break; EmT_T3v
|c0^7vrC
YtvDayR>
//count++; 01o<eZ,
//if(count>4) yP3I^>AZ3
// siteStop(); e;XRH<LhAU
} m OUO)[6y
HY5R
}o:LwxNO
System.err.println("文件下载结束！"); `W1uU=c
} KMi$0+
catch(Exception e){e.printStackTrace ();} >s/_B//[
} [;ZCq!)>
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@H`jDaB9
//获得文件长度 sPQjB[
public long getFileSize() S~:uOm2t\
{ r2#G|/=@
int nFileLength = -1; lUjZ=3"'
try{ L~PiDQr?r
URL url = new URL(siteInfoBean.getSSiteURL()); {g nl6+j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~4+Y BN
httpConnection.setRequestProperty("User-Agent","NetFox"); 'sIne>
O W.CU=XU
w98M#GqV
int responseCode=httpConnection.getResponseCode(); VX8rM!3
if(responseCode>=400) 1_{e*=/y
{ H4`>B>\
processErrorCode(responseCode); .pPuBJL]<
return -2; //-2 represent access is error b|AjB:G
} wzy[sB274
-KC@M
@}6<,;|DQ
String sHeader; 1P"7.{
W)ug%@)
2 )o2d^^
for(int i=1;;i++) Ut2T:%m{
{ 424iFc[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ykbfK$jz
//Utility.log(in.readLine()); ]CNPy$>*
sHeader=httpConnection.getHeaderFieldKey(i); bxYSZCo*
if(sHeader!=null) b * \ oQ
{ Ry}4MEq]
if(sHeader.equals("Content-Length")) 2fkyz
{ &*/= `=:C8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uT=r*p(v
break; h'S0XU ;
} TP#Ncqh
} <xeB9
else "Q+wO+}6
break; ~/A2:}Cp=
} NpGi3>5
} >QYx9`x&
catch(IOException e){e.printStackTrace ();} VfzyBjQ
catch(Exception e){e.printStackTrace ();} cr-5t4<jK
KJJ:fG8'
j_,/U^Ws|f
Utility.log(nFileLength); E8av/O VUd
=_=%1rI~
!EKt$8W
return nFileLength; axmq/8X
} 7Ku&Q<mi
1v:Ql\^cT
4I&(>9 @z<
//保存下载信息（文件指针位置） 6t7FklM%
private void write_nPos() j.6!T'$|
{ ZFMO;'m&
try{ mg:kVS
output = new DataOutputStream(new FileOutputStream(tmpFile)); O1jiD_Y!9
output.writeInt(nStartPos.length); #m{(aa9;
for(int i=0;i<nStartPos.length;i++) C+t3a@&|
{ K?,?.!ev
// output.writeLong(nPos); 4r_*: $g
output.writeLong(fileSplitterFetch.nStartPos); '2Zs15)V
output.writeLong(fileSplitterFetch.nEndPos); '%/=\Q`
} y(<{e~
output.close(); AVLY|79#
} tt-ci,X+
catch(IOException e){e.printStackTrace ();} G0h&0e{w
catch(Exception e){e.printStackTrace ();} KsIHJr7-
} ,k_ b-/
<=_!8A
e}5x6t
//读取保存的下载信息（文件指针位置） ~*3Si(4l/
private void read_nPos() 7R[7M%H
{ Z0H_l/g
try{ =LIb0TZ2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IR3SP[K"
int nCount = input.readInt(); v(Kj6'
nStartPos = new long[nCount]; - s'W^(
nEndPos = new long[nCount]; Q'jGNWep
for(int i=0;i<nStartPos.length;i++) eXsp0!v
{ ~rI2 RJ
nStartPos = input.readLong(); 6wpu[
nEndPos = input.readLong(); mEYfsO
} P%&|?e~D^
input.close(); `0%;Gz%}
} 7./WS,49
catch(IOException e){e.printStackTrace ();} XBX`L"0
catch(Exception e){e.printStackTrace ();} ?99r>01>
} Ie!">8."
}BW&1*M{
Chl^LEN:
private void processErrorCode(int nErrorCode) dY.X/f
{ 9ec?L
System.err.println("Error Code : " + nErrorCode); ye(av&Hn
} %VB4/~ "
sa<\nH$_X
;~r-P$kCY
//停止文件下载 ]O:u9If
public void siteStop() U.Vn|s(`z
{ xX<T5Ls
bStop = true; |1H9,:*%
for(int i=0;i<nStartPos.length;i++) AXxyB"7A}
fileSplitterFetch.splitterStop(); O0rvr$.
&b,A-1`w_
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} 416}# Mk
} #k/T\PQ0s
//负责部分文件的抓取 }LS.bQKqi,
**FileSplitterFetch.java +68age;dM
*/ 6qmV/DL
package NetFox; ^GYVRD
/ho7~C+H*e
J"h2"$v,
import java.io.*; 7gOu|t
import java.net.*; pk'd&.
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public class FileSplitterFetch extends Thread { $<=d[6
2h<_?GM\s
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String sURL; //File URL 4W2.K0Ca
long nStartPos; //File Snippet Start Position <#"_Qgdix
long nEndPos; //File Snippet End Position ~x4]p|)</
int nThreadID; //Thread's ID ^^ SMr l
boolean bDownOver = false; //Downing is over ^o>WCU=
boolean bStop = false; //Stop identical OXZK|C;M}
FileAccessI fileAccessI = null; //File Access interface hN0h'JJ[7
T ;84Sv
T>*G1-J#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <2kv/
{ O5:U2o-
this.sURL = sURL; r91i :
this.nStartPos = nStart; sqF.,A,
this.nEndPos = nEnd; zV15d91GX
nThreadID = id; /W f.Gt9[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DfGq m-c
} oPBKPGD
=B+dhZ+#S$
t{s>B]i^_w
public void run() ]!1HN3
{ ZvXw#0)v
while(nStartPos < nEndPos && !bStop) +3AX1o%p,#
{ 8kd):gZKZ
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(6H7?nv
try{ =],c$)
URL url = new URL(sURL); P!j*4t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]C+PJ:CC
httpConnection.setRequestProperty("User-Agent","NetFox"); kuLur)^
String sProperty = "bytes="+nStartPos+"-"; 2YQBw,gG
httpConnection.setRequestProperty("RANGE",sProperty); 5i{J0/'Xu)
Utility.log(sProperty); IcqzMmb
@o}J)
<o|k'Y(-
InputStream input = httpConnection.getInputStream(); YsiH=x
//logResponseHead(httpConnection); dKXzFyW
%RwWyzm#\
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byte[] b = new byte[1024]; 9T$%^H9
int nRead; >D##94PZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h<'tQGC
{ ??#EG{{
nStartPos += fileAccessI.write(b,0,nRead); /18fpH|
//if(nThreadID == 1) DH$Nz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K'Wv$[~Dc
} ;sUvY*Bcm
cw0@Z0
#jxPh!%9
Utility.log("Thread " + nThreadID + " is over!"); p}I\H ^"8+
bDownOver = true; x6\VIP"9L
//nPos = fileAccessI.write (b,0,nRead); v13\y^t
} 4u0?[v[Hu
catch(Exception e){e.printStackTrace ();} 6_rgRo&
} JX>`N5s
} j~+(#|
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Xa"I
//打印回应的头信息 C[ KMaB
public void logResponseHead(HttpURLConnection con) &0ymAf5R
{ ~EQ# %db
for(int i=1;;i++) y'oH>l+n
{ \ ux{J
String header=con.getHeaderFieldKey(i); |Q%nnN
if(header!=null) [z_ztK1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xu]Kt+QnSk
Utility.log(header+" : "+con.getHeaderField(header)); FL$S_JAw
else 1B 0[dK2N
break; n#?y;Y\
} +uNMyVH
} p? VDBAx
wJgH15oB
SuV3$-);z
public void splitterStop() #4nBov3d
{ g38MF
bStop = true; .k up[d(
} <O-R
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j,i)ecZ>
} DbR!s1ux
<ZO+e*4
vy-(:aH7U
/* K1;b4Sl?A
**FileAccess.java hv|-`}#0
*//文件访问(定位，写) ycIcM~<4
package NetFox; 1Z(9<M1!M
import java.io.*; ]_!NmB_3
]}&HvrOld
.M[t5I'\
public class FileAccessI implements Serializable{ xA*6Z)Y
AS4oz:B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ='e_9b\K
RandomAccessFile oSavedFile; ;kG"m7-/
long nPos; < jX5}@`z
9RK.+2
I&&;a.
public FileAccessI() throws IOException MQ'=qR
{ $.ctlWS8l{
this("",0); [ 'B u
} S%G&{5
z 7cA5'c
a=B $L6*4
public FileAccessI(String sName,long nPos) throws IOException %82:?fq
{ v[DxWs8q
oSavedFile = new RandomAccessFile(sName,"rw"); xj]^<oi<
this.nPos = nPos; Efpju(
oSavedFile.seek(nPos); e+m(g
} 3Zpq#
\mt Y_O
NUtKT~V
public synchronized int write(byte[] b,int nStart,int nLen) O2lM;="
{ \ZSqZDq
int n = -1; :"i2`y;u
try{ ( pCU:'"
oSavedFile.write(b,nStart,nLen); ^7:UC\_
n = nLen; B'PS-Jr
} T#H-GOY:
catch(IOException e) ^%U`|GBZp
{ +t]Ge >S
e.printStackTrace (); J'I1NeK
} p7.~k1h
pQ ul0]
zf\$T,t)
return n; :$XlYJrjK
} -<u_fv
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#,"[sag
} u0ZMrIJ
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*m'&<pg]X
/* ?|Wxqo
**SiteInfoBean.java 95/;II
*/ A=D G+z''
package NetFox; 9'vf2) "
vNm4xa%
}h sR}
public class SiteInfoBean { m&MZn2u[4i
kFfNDM#D
zvv/|z2(r
private String sSiteURL; //Site's URL }Os7[4RW
private String sFilePath; //Saved File's Path @JJ{\?>
private String sFileName; //Saved File's Name ,s,AkH
private int nSplitter; //Count of Splited Downloading File s`]SK^j0
G2=dq
4~d:@Gmk&
public SiteInfoBean() `0u)/s$
{//nSplitter的缺省值为5 ki?V eFp
//default value of nSplitter is 5 =,s5>2
this("","","",5); 1l.HQ IS
} -(#`JT8
4Le{|B
qzu(4*Gk6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |k: FNu]C
{ Jg.^h1>x
sSiteURL= sURL; 1 a%1C`d
sFilePath = sPath; #A< |qd
sFileName = sName; !H9zd\wc
this.nSplitter = nSpiltter; LZJFp@
DKNcp8<J
#)%X0%9.*<
} &5%~Qw..
+N|t:8qaf
ciCQe]fS
public String getSSiteURL() Xw162/:h
{ a{.-qp
return sSiteURL; Pf3F)y[=
} oSO~72
g(o^'f
WjvgDNk
public void setSSiteURL(String value) 6x16?x
{ P qa;fiJ)
sSiteURL = value; Rf{YASPIw&
} q9Lq+4\
h,MaF<~
&sJ6k/l
public String getSFilePath() >ATccv
{ #Xi9O.
return sFilePath; <CS,v)4,nH
} @8cn<+"b
i06|P I
T4;gF6(0]
public void setSFilePath(String value) {CgF{7`
{ * YLpC^&
sFilePath = value; d(,M
} cfc=a
ypTH=]y
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public String getSFileName() ;F/w&u.n
{ }l5Q0'
return sFileName; ~yY5pnJ
} V$ "]f6
UrdSo"%
1f$1~5Z
public void setSFileName(String value) J c:j7}OOV
{ jZ<f-Ff0
sFileName = value; .6iJ:A6T
} b C"rQJg
k!g%vx
v;s^j
public int getNSplitter() C]krJse@
{ sQO>1bh
return nSplitter; 9*(uJA
} K6nNrd}p:
I%mGb$Q
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public void setNSplitter(int nCount) $KsB'BZy
{ 8y]{I^z}
nSplitter = nCount; .h@bp1)l
} yDi'@Z9R?
} k.%FGn'fR
r<$"T
;4*mUD6
/* lt{"N'Gw6
**Utility.java @:P:`Zk
*/ ~mT([V
package NetFox; dF+:9iiAm
r3~YGY
=^w:G=ymS
public class Utility { w2V:g$~,
z[]8"C=
3o_@3-Y%
public Utility() .R&jRtb/E
{ n-CFB:L
Z07SK 'U
oox;8d4}y
} ezhK[/E=
LP}'upv
//线程睡眠 ({hW
public static void sleep(int nSecond) S"R(6:hkgu
{ @KU^B_{i
try{ (_Rl f$D
Thread.sleep(nSecond); B1J2m^
} }`_x%]EJ
catch(Exception e) _Hv@bIL'
{ 1sXVuto
e.printStackTrace (); T{*!.+E
} W"5VqN6v
} GO6uQ};
D|/ 4),v
//日志 (5)DQ1LaF
public static void log(String sMsg) ]KQBek#DD
{ ]fU0;jzX
System.err.println(sMsg); vk3C&!M<a
} YDGW]T]i ?
v(Q-RR
35~1$uRA
public static void log(int sMsg) F?4&qbdD
{ i5czm?x
System.err.println(sMsg); "lKR~Qi
} f<Yg_TG
} IGI$,C
:\|<7n
1*OZu.NdK
/* 8/W2;>?wKc
**TestMethod.java [f`7+RHrd
*/ 8LGNV&Edg
package NetFox; OJ<V<=MYZ
#M[%JTTn
}i9VV+L#1
public class TestMethod { 32K
f+4j ^y}
)/BbASO$)Z
public TestMethod() 6f;20dn6
{ ///xx/weblogic60b2_win.exe Pq3|O Z
try{ evz@c)8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =L,7~9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )_1;mc8B
SiteFileFetch fileFetch = new SiteFileFetch(bean); +.66Ky`|[
fileFetch.start(); %kV #UzL
} 4X$|jGQ\
catch(Exception e){e.printStackTrace ();} _{?-=<V'_
m 8P`n
;~n^/D2.
} n?8xRaEf
}}zY]A
luCwP
public static void main(String[] args) @"/:Omh
{ RFLw)IWkL_
new TestMethod(); Mo[yRRS#
} +sx$%N
} |) CfO4
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