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)); bzX\IrJpOZ
} GlbySD@
for(int i=0;i<nEndPos.length-1;i++) dHK`eS$sb
{ wvbPnf^y
nEndPos = nStartPos[i+1]; e XfZ5(na
} 7VMvF/ap]u
nEndPos[nEndPos.length-1] = nFileLength; u86"Y^d#
} xKQ+{"?-^g
} *M$0J'-BQ
gF$V$cU
Aj2OkD
//启动子线程 ~ECD`N<YF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r6&54f
for(int i=0;i<nStartPos.length;i++) ,Fi>p0bz
{ HYD"#m'TkB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >B2:kY F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WDg+J
nStartPos,nEndPos,i); $OP7l>KZY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z\HX~*,6
fileSplitterFetch.start(); `FsH}UPu b
} z)9wXo#~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xtp"QY p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); uO=aaKG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +"8,Mh
nEndPos = " + nFileLength); \ gLHi~
// fileSplitterFetch[nPos.length-1].start(); |b*? qf
^4,a8`
)hk
//等待子线程结束 tI7:5Cm
//int count = 0; G3rj`Sg^c
//是否结束while循环 JaK}|
boolean breakWhile = false; ,t`Kv1
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while(!bStop) |37 g ~
{ K91)qI;BD
write_nPos(); P&b19K'
Utility.sleep(500); nS&3?lx9_
breakWhile = true; zxf"87se
f-5:wM&
VY)9|JJCO
for(int i=0;i<nStartPos.length;i++) z}{afEb
{ #{=;NuP
if(!fileSplitterFetch.bDownOver) x-?{E
{ :PtF+{N>
breakWhile = false; ppFe-wY
break; tUgEeh6
} 2Sh
} NMww>80
if(breakWhile) vP!{",>
break; K^B%/T]d
J,zO2572u
4"xPr[=iG
//count++; cCa|YW^j
//if(count>4) NcP.;u;`
// siteStop(); {;.T7dL
} 2D:fJ~|-[
?c7*_<W5
A?`jnRo=\
System.err.println("文件下载结束！"); Zc!@0
} e'=MQ,EWd
catch(Exception e){e.printStackTrace ();} C-Ht(x|
} zkO<-w
!}4MN:r
,:`ND28V7
//获得文件长度 JB>b`W9
public long getFileSize() A0fFv+RN3
{ (sQr X{~
int nFileLength = -1; I(9R~q
try{ "h|'}7p
URL url = new URL(siteInfoBean.getSSiteURL()); 9Ffp2NW`;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _z54Ycr4H
httpConnection.setRequestProperty("User-Agent","NetFox"); C#H:-Q&
i| ZceX/
Bf$_XG3
int responseCode=httpConnection.getResponseCode(); #?XQ7Im
if(responseCode>=400) l2&`J_"
{ (XXheC
processErrorCode(responseCode); P9S2?Q
return -2; //-2 represent access is error |QMhMGjV
} V=lfl1Ev0J
*bxzCI7b
> ]8a3x
String sHeader; "3<da*D1
Zr-U&9.`
JR@.R ,rII
for(int i=1;;i++) j~FD{%4N
{ ~j-cS J3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #Jna6
//Utility.log(in.readLine()); HmZ{L +"
sHeader=httpConnection.getHeaderFieldKey(i); uio@r^Xz
if(sHeader!=null) KL ?@@7
{ :Dd$i_3=
if(sHeader.equals("Content-Length")) +n7?S~R$
{ \'M3|w`f
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~u.T-0F
break; .S%0
} JkGnKm9G
} ;A'":vXmc
else cW{1 Pz^_
break; iR\Hv'|
} D)@YI.T
} 0jzbG]pc:E
catch(IOException e){e.printStackTrace ();} @o-B{EH8
catch(Exception e){e.printStackTrace ();} LC})ciWa
fd#jY}
e4G4GZH8
Utility.log(nFileLength); '*Almv{
YOrrkbJ(
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return nFileLength; 8kbY+W%n
} g/&T[FOr
t!2(7=P30(
Vf`7V$sr
//保存下载信息（文件指针位置） 5BR2?hO4
private void write_nPos() wP57Pf0
{ I"1;|`L~:
try{ @&"Pci+-|
output = new DataOutputStream(new FileOutputStream(tmpFile)); jM&r{^(
output.writeInt(nStartPos.length); E( h<$w8s
for(int i=0;i<nStartPos.length;i++) TI !a)X
{ |TE}`?y[g
// output.writeLong(nPos); gh>>Ibf
output.writeLong(fileSplitterFetch.nStartPos); .7 asW(
output.writeLong(fileSplitterFetch.nEndPos); gaf$uT2
} @A+RVg*=
output.close(); ex<O]kPFE
} suH&jE$x
catch(IOException e){e.printStackTrace ();} gt\MS;jMa
catch(Exception e){e.printStackTrace ();} :d8W+|1u
} cv(PP-'\
Q.Aw2
<jS~ WI@
//读取保存的下载信息（文件指针位置） 5~.ZlGd
private void read_nPos() unJ R=~E
{ U#n#7G6fRp
try{ KK,Z"){
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QaGlR`Y
int nCount = input.readInt(); 9 C{;h
nStartPos = new long[nCount]; 4G@nZn
nEndPos = new long[nCount]; \j2;4O?`
for(int i=0;i<nStartPos.length;i++) hb/]8mR
{ NjE</Empb%
nStartPos = input.readLong(); v?c 0[+?
nEndPos = input.readLong(); g}f9dB,F
} {ls+dx/
input.close(); {}o>{&X
} W[[bV
catch(IOException e){e.printStackTrace ();} Fxc)}i`
catch(Exception e){e.printStackTrace ();} dDDGM:]
} kF;5L)o
X1tXqHJF}
t |W)
private void processErrorCode(int nErrorCode) -B$~`2-
{ u4"SH(
System.err.println("Error Code : " + nErrorCode); Uu7dSU
} n}mR~YqD
JjXobNQf
9e U[*S
//停止文件下载 E(Rh#+]Y5
public void siteStop() =&dW(uyzY
{ pr,p=4m{\
bStop = true; $^ 'aCU0C
for(int i=0;i<nStartPos.length;i++) $DBGLmw
fileSplitterFetch.splitterStop(); AOp/d(vx5i
0e[d=)XG
=op%8NJf
} qi^!GA'5j
} #,(sAj
//负责部分文件的抓取 q@hp.(V
**FileSplitterFetch.java >O/D!j|
*/ !'=15&5@
package NetFox; }<jb vCeK
mfny4R1_
-;;Z 'NM;8
import java.io.*; i{^Z1;Yl
import java.net.*; ^O^:$nXhYy
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Q{QYBh&
public class FileSplitterFetch extends Thread { INSkgOo
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String sURL; //File URL N:VX!w
long nStartPos; //File Snippet Start Position W YW|P2*
long nEndPos; //File Snippet End Position T88Y qI
int nThreadID; //Thread's ID QIB>rQCceo
boolean bDownOver = false; //Downing is over IgL_5A
boolean bStop = false; //Stop identical xKOq[d/8
FileAccessI fileAccessI = null; //File Access interface CY?G*nS?iK
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5~XN>>hp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ":Edu,6O
{ Lh$dzHq
this.sURL = sURL; ~Z$bf>[(R7
this.nStartPos = nStart; rSP_:}
this.nEndPos = nEnd; ?RFg$Z'^
nThreadID = id; K:y^OAZfV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7?"y{R>E
} 3}1ssU"T
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s|bM%!$1
public void run() ~F, &GH
{ ?v}Bd!'+P
while(nStartPos < nEndPos && !bStop) '[P}&<ie,
{ P ,eH5w"
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L3(^{W]|
try{ 1+y"i<3)
URL url = new URL(sURL); Zt3}Z4d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?lCd{14Mkh
httpConnection.setRequestProperty("User-Agent","NetFox"); N?4q
String sProperty = "bytes="+nStartPos+"-"; RAs0]K
httpConnection.setRequestProperty("RANGE",sProperty); io4A>>W==/
Utility.log(sProperty); \'?#i@O
qBk``!|s]
;/AG@$)
InputStream input = httpConnection.getInputStream(); TB aVW
//logResponseHead(httpConnection); J?:[$C5
)wzV $(~
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byte[] b = new byte[1024]; Q}2[hB
int nRead; dpN@#w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }b["Jk\2
{ b1^n KB
nStartPos += fileAccessI.write(b,0,nRead); )E7 FA|
//if(nThreadID == 1) 7_KhV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CidM(
} jkrx]`A{~
&$fbP5uAZ
R -elIp
Utility.log("Thread " + nThreadID + " is over!"); |@VF.)_
bDownOver = true; _EYB 8e
//nPos = fileAccessI.write (b,0,nRead); vrl[BPI
} Sg*0[a3z
catch(Exception e){e.printStackTrace ();} =F%RLpNU4
} v1[_}N9f>H
} mU{4g`Iw
nZvU'k:
"4}wnu6/
//打印回应的头信息 u"VS* hSH
public void logResponseHead(HttpURLConnection con) q7]>i!A
{ f$xhb3Qn
for(int i=1;;i++) !)H*r|*[
{ \%_ZV9cKF
String header=con.getHeaderFieldKey(i); M StX*Zw
if(header!=null) M?6;|-HH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B1T5f1;uY
Utility.log(header+" : "+con.getHeaderField(header)); Q^h5">P
else w{7ji}
break; mc@M,2@D
} Z^6#4Q]YC
} 0o/B{|rv
NtZ6$o<Y
B%b_/F]e
public void splitterStop() 3XVk#)lw
{ -Ds|qzrN%
bStop = true; Sb<\-O14"
} pzEABA
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} i-13~Dk
1Ii| {vR
Xem| o&
/* V/H@vKN2
**FileAccess.java p?Sl}A@`
*//文件访问(定位，写) Zc\S$+PM
package NetFox; ,olwwv_8G
import java.io.*; 3q~Fl=|.o
@InJ_9E
k:0P+d
public class FileAccessI implements Serializable{ %]jQ48^R
r{"uv=,`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .Vh*Z<9S4
RandomAccessFile oSavedFile; |3@=CE7G
long nPos; {E~l>Z88
syFI$rf _
)fCMITq.|
public FileAccessI() throws IOException f'_S1\
{ SI_?~Pf3k
this("",0); t,Q'S`eTU
} Y+qus
qc-C>Ra
|BJqy/
public FileAccessI(String sName,long nPos) throws IOException x(6vh2#vD
{ +u#Sl)F
oSavedFile = new RandomAccessFile(sName,"rw"); `@\^m_!}
this.nPos = nPos; {,v: GMsm
oSavedFile.seek(nPos); C9Wojo.
} 44Qk;8*
?Q:PPqQ
>ZDC . ~
public synchronized int write(byte[] b,int nStart,int nLen) q]ZSjJ
{ syMm`/*/G-
int n = -1; J{H?xc o
try{ 0Q3YN(
oSavedFile.write(b,nStart,nLen); ?H0m<jO8~
n = nLen; \*9Ua/H
} 8_awMVAy
catch(IOException e) ~h|m&XK+Q
{ |$Xf;N37t
e.printStackTrace (); XW:%vJu^`
} &fHc"-U}
\)GR\~z0h
d"l}Ny)C
return n; y{;u@o?T
} KDaN-r^{%
4g'}h`kh
TMtI^mkB:
} LH.%\TMN$
i0i`k^bA
.' IeHh
/* Q %y,;N"ro
**SiteInfoBean.java rBD2Si=
*/ cl2ze
package NetFox; .r*#OUC
,#Ln/;
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public class SiteInfoBean { M)tv;!eQ
m|`VJ0
I9Om#m
private String sSiteURL; //Site's URL @|]G0&gn&?
private String sFilePath; //Saved File's Path l}+Cdy9>
private String sFileName; //Saved File's Name 5])8qb/F
private int nSplitter; //Count of Splited Downloading File @dl<-
QP<FCmt8
6.UKB<sV
public SiteInfoBean() fT x4vlI4
{//nSplitter的缺省值为5 ] EV`dIk
//default value of nSplitter is 5 ~RCg.&[ou
this("","","",5); M0L-u
} 7>KQRLw
.CvFE~
)ZeLaaP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 79a9L{gso
{ n8Q* _?Z/
sSiteURL= sURL; p*!q}%U
sFilePath = sPath; <YSg~T
sFileName = sName; ,.q8Xf
this.nSplitter = nSpiltter; [Q=4P*G}X
M.t@@wq
z2ds8-z
} pbFYiu+
e-jw^
" C&x,Ic
public String getSSiteURL() wU.'_SBfB
{ xLZMpP5c
return sSiteURL; @,GjeF]!
} .2/,XwIr
!b'IfDp[-!
^}tLnF
public void setSSiteURL(String value) wyNC|P;j$g
{ =}"R5
sSiteURL = value; "W3W:vl!
} 3 ^pYCK%
:K:f^o]s
jB`7T^bU
public String getSFilePath() a&8l[xe1
{ q'by;g*m
return sFilePath; XS3{R
} V15q01bE#
# UjEY9"M
.byc;9M%
public void setSFilePath(String value) [:Xn6)qz
{ H a90
sFilePath = value; l,^xX=,
} rAL1TU(vm
n}42'9p
J&'>IA
public String getSFileName() \I:UC %
{ P`z7@9*j
return sFileName; (2cGHYU3N<
} ktU9LW~
n}+wd9J*!2
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public void setSFileName(String value) 2$iw/r
{ ]}_p3W "Y9
sFileName = value; @h!U
} cxL,]27Bu
s87 a%
,!jR:nApE
public int getNSplitter() <` #,AVH
{ |G>q:]+AV
return nSplitter; 5s#R`o%Z
} sw[<VsxjR
4$..r4@
yY'gx|\
public void setNSplitter(int nCount) pb~Ps#"Zg
{ PkjT&e)
nSplitter = nCount; -6(h@F%E
} 5sG ]3z+1
} ]aREQ?ma&z
*X%?3"WH8
L,f^mX0<
/* D`1I;Tb#
**Utility.java Ml'bZLwq
*/ loml.e=87
package NetFox; rve7YS'
jM{qRfOrg
\MfR #k0
public class Utility { |:~("rA+v
*QMF <ze
Ma% E&.ed
public Utility() D%6ir*%T
{ w2.qT+;v
jn0t-":
|G[{{qZM5
} ]}jgB2x7
.WxFm@]/\
//线程睡眠 Bk\*0B
public static void sleep(int nSecond) Rc$=+K#
{ "(9=h@@Y"
try{ ['Hp?Q|k
Thread.sleep(nSecond); ?IL! X-xx
} Sn;/;^@(\
catch(Exception e) n%7A;l!{
{ ?,.HA@T%
e.printStackTrace (); B)_!F`9
} E|KLK4]
} BnY\FQ)K
V5hp Y ]
//日志 95_[r$C
public static void log(String sMsg) 46QYXmNQ}
{ <|mE9u
System.err.println(sMsg); ,e}mR>i=e
} *?EjYI
fx8y`8}_
ZE5-i@1
public static void log(int sMsg) 2<`gs(oxXe
{ |6\FI?
System.err.println(sMsg); V2WUM+`uT
} -MVNXAKnZ
} ^(E"3 c
'XC&BWJ
nPQZI6>
/* r*~n`
**TestMethod.java '[7C~r{%
*/ >[A65q'
package NetFox; Om&{4a\
dVY(V&p
Q' OuZKhA
public class TestMethod { RZcx4fL}x
RPa?Nv?e
Z&?+&q r^
public TestMethod() "<g?x`iz
{ ///xx/weblogic60b2_win.exe ]%vGC^
try{ .j'@K+<45
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uIVTs9\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *!wO:<-
SiteFileFetch fileFetch = new SiteFileFetch(bean); .3S\Rrv
fileFetch.start(); ,_wm,
} E@\d<c.
catch(Exception e){e.printStackTrace ();} 3Vb=6-|
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%_%f#S
} |wyJh"4!
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l,^i5t'
public static void main(String[] args) 8Izn'>"
{ V PLCic,T
new TestMethod(); UIm[DYMS
} (}/.4xE
} R-2FNl
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