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)); 6`4W,
} Y zBA{FE
for(int i=0;i<nEndPos.length-1;i++) /@:up+$
{ nc\C4g
nEndPos = nStartPos[i+1]; ? __aVQ7
} d7_g u
nEndPos[nEndPos.length-1] = nFileLength; VM]GYz|#]
} N{hF [F
} *e-ptgO
,y8I)+
<jRFN&"h}
//启动子线程 6mF{ImbRbS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {r].SrW9s9
for(int i=0;i<nStartPos.length;i++) mj(&`HRs4
{ Mi/ &$"=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]Ic?:lKN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V^`?8P8d
nStartPos,nEndPos,i); (+gL#/u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |:(23O
fileSplitterFetch.start(); :B*vkwT
} ^QXw[th!d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zOiY0`=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Rgfc29(8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =,C9O
nEndPos = " + nFileLength); D-o7yc"K
// fileSplitterFetch[nPos.length-1].start(); 8R)D! 7[l
3m43nJ.~
"'F;lzq
//等待子线程结束 0Y6q$h>4
//int count = 0; gP%|:"
//是否结束while循环 DD@)z0W
boolean breakWhile = false; O+E1M=R6h
S}m$,<x
1(%>`=R8
while(!bStop) @Ge>i5q
{ oxMUW<gYd
write_nPos(); aW=By)S!Y
Utility.sleep(500); PHRGhKJW})
breakWhile = true; 9b"9m*gC
`s>UU- 9
4{*tn"y
for(int i=0;i<nStartPos.length;i++) |ilv|UV
{ L8bI0a]r"*
if(!fileSplitterFetch.bDownOver) OBI+<2`Oc
{ 7ZV~op2Q
breakWhile = false; up3?$hUc.
break; T}n}.JwU
} J+}+"h~.
} {ywXz|TP
if(breakWhile) (@KoqwVWc
break; o9m
tIGVB+g{F
w\o)bn
//count++; + %MO7vL
//if(count>4) d`9W
// siteStop(); pwFU2}I
} FpdDIa
]3O 4\o
Wa[x`:cT?u
System.err.println("文件下载结束！"); e~+(7_2
} f=:3!k,S
catch(Exception e){e.printStackTrace ();} KMK&[E#r
} IU Y> ih
:H!(?(Pie
@,x_i8
//获得文件长度 6%gB E
public long getFileSize() E\]OySC%C$
{ Y8)E]D
int nFileLength = -1; MvFM,
try{ J$#h(D%
URL url = new URL(siteInfoBean.getSSiteURL()); {J,6iP{>ZN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a>wfhmr
httpConnection.setRequestProperty("User-Agent","NetFox"); ]UX`=+{
. ]o3A8
2E`~ qn
int responseCode=httpConnection.getResponseCode(); \!+-4,CbZY
if(responseCode>=400) [ME}Cv`?<E
{ u\{qH!?t
processErrorCode(responseCode); ]Q6+e(:~ZH
return -2; //-2 represent access is error I#|ocz
} .q0218l:dF
;YK!EMM4!h
Aautih@LX
String sHeader; Q'Jv}'eK_
Ni2]6U
H+4=|mkQ
for(int i=1;;i++) {8^Gs^c c
{ <u/a`E?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _4P;+Y
//Utility.log(in.readLine()); U/T4i#
sHeader=httpConnection.getHeaderFieldKey(i); xT9Yes&
if(sHeader!=null) ''#p47$8<d
{ ?mH@`c,fM
if(sHeader.equals("Content-Length")) ],;D2]<s
{ 5/& 1Oxo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `%-4>jI9-
break; Y]C;T
} hc-lzYS
} /635B*g
else r1i$D
break; `IEq@Wr#$!
} 79)A%@YHQQ
} ;yF[2P ;
catch(IOException e){e.printStackTrace ();} 0o=!j3RjH
catch(Exception e){e.printStackTrace ();} cu[!D}tVU
5^)?mA
#v.L$7O
Utility.log(nFileLength); \'n$&PFe
X'cf&>h
u-m%=2
return nFileLength; Q`H# fS~
} '5'3_vM
w[ Axs8N'
mfXD1]<.
//保存下载信息（文件指针位置） `.{U-U\
private void write_nPos() ; D1FAz
{ 5a'yXB}
try{ hP?7zz$*j
output = new DataOutputStream(new FileOutputStream(tmpFile)); WK pUn8&N
output.writeInt(nStartPos.length); /&CUspb
for(int i=0;i<nStartPos.length;i++) CV'&4oq
{ *"1~bPl
// output.writeLong(nPos); ; ;<J x.
output.writeLong(fileSplitterFetch.nStartPos); l`SK*Bm~<
output.writeLong(fileSplitterFetch.nEndPos); ./$ <J6-J
} q1H=/[a
output.close(); 53B.2 4Tm
} S[vRw]*
catch(IOException e){e.printStackTrace ();} JW=uK$sO
catch(Exception e){e.printStackTrace ();} Yt -W1vl
} @4;&hP2Z:
@gNpJB]V
~eDI$IO
//读取保存的下载信息（文件指针位置） K} +S+ *_
private void read_nPos() 5N\+@grp
{ 8KFj<N>'
try{ {={^6@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P3G:th@j=
int nCount = input.readInt(); sp|q((z{
nStartPos = new long[nCount]; +9RJ%i&Ec
nEndPos = new long[nCount]; =M/qV
for(int i=0;i<nStartPos.length;i++) : (cb2j(C
{ :3v9h^|+
nStartPos = input.readLong(); <nBo}0O}
nEndPos = input.readLong(); PNf&@
} Y+FP
input.close(); qYx!jA]O
} @|DmE!)
catch(IOException e){e.printStackTrace ();} pjACFVMFX
catch(Exception e){e.printStackTrace ();} zt?h^zf}
} 0A.PD rM:
_ j~4+H
oew|23Ytb
private void processErrorCode(int nErrorCode) qmEoqU
{ z OtkC3hY
System.err.println("Error Code : " + nErrorCode); f3!n$lj
} _74UdD{^o
m=H_?W;
Vn'?3Eb<
//停止文件下载 P@C c]Z
public void siteStop() `mrCu>7
{ |"Z-7@/k$i
bStop = true; D ZVXz|g
for(int i=0;i<nStartPos.length;i++) 3)Zu[c[%'J
fileSplitterFetch.splitterStop(); Vb2\/e:k
ZW>o5x__b
4Q;<Q"
} Lx%:t YZ
} HcA[QBh
//负责部分文件的抓取 [<yz)<<
**FileSplitterFetch.java PB+\jj
*/ 5C B%=iL{
package NetFox; g92dw<$>
Hq?&Qo
yxvjg\!&
import java.io.*; PcB{=L
import java.net.*; 0(8gQ 2n
DcN"=Y
'j}g
public class FileSplitterFetch extends Thread { ehE-SrkU'
-,^WaB7u\
%*jGim~s
String sURL; //File URL :W~f;k
long nStartPos; //File Snippet Start Position eES'}[W>
long nEndPos; //File Snippet End Position as(*B-_n~
int nThreadID; //Thread's ID jn^fgH?
boolean bDownOver = false; //Downing is over Oxv+1Ub<Dv
boolean bStop = false; //Stop identical G,]z(%
FileAccessI fileAccessI = null; //File Access interface bEd?^h
zks#EzQ
;,rnk-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d@ZoV
{ /ERNS/w
this.sURL = sURL; !R74J=#(
this.nStartPos = nStart; ?I[h~vr6.
this.nEndPos = nEnd; ^!}F%
nThreadID = id; iS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ihg~Q4t
} VHW`NP 5Jl
,E?4f @|X
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public void run() Ukc'?p,*
{ jn$j^51`C
while(nStartPos < nEndPos && !bStop) wWTQ6~Y%d
{ #/+I*B*y
y@3kU*-1
akC>s8tqlA
try{ )Oievu_"|
URL url = new URL(sURL); b+Vi3V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @h#Xix7
httpConnection.setRequestProperty("User-Agent","NetFox"); i=L8=8B`
String sProperty = "bytes="+nStartPos+"-"; 1"O&40l
httpConnection.setRequestProperty("RANGE",sProperty); 4)^vMG&
Utility.log(sProperty); RL*]g*
TT7PQf >
P?J kP
InputStream input = httpConnection.getInputStream(); /PqUXF
//logResponseHead(httpConnection); :G 5C ]'t
6R2uWv
4%7s259%
byte[] b = new byte[1024]; 4.Z(:g
int nRead; ~^$MA$/p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g\&2s,
{ =Z`0>R`
nStartPos += fileAccessI.write(b,0,nRead); >A($8=+#x
//if(nThreadID == 1) U Du~2%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HN68!v}C|
} cy3M^_5B<
fK_~lGY(
;Iq5|rzDn
Utility.log("Thread " + nThreadID + " is over!"); K_#UZA< Y
bDownOver = true; uNbIX:L,
//nPos = fileAccessI.write (b,0,nRead); {y6C0A*
} 5 `=KyHi:b
catch(Exception e){e.printStackTrace ();} t77'fm
} &XQZs`41+
} ltSh'w0
S?4KC^Y5
x: ~d@
//打印回应的头信息 a5?A!k\2
public void logResponseHead(HttpURLConnection con) B{aU;{1
{ @9vvR7{P
for(int i=1;;i++) tOH0IE c
{ zMGzReJ
String header=con.getHeaderFieldKey(i); >vVw!.fJ
if(header!=null) -:SIS`0s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); El (/em
Utility.log(header+" : "+con.getHeaderField(header)); 8l23%iWxe
else S+ebO/$>
break; b_vTGl1_6
} 3dG4pl~
} %[Zz0|A
lzDdD3Ouc
]"sRS`0+
public void splitterStop() v[&'k\
{ ,I`_F,
bStop = true; tD-gc''H
} _whF^g8
|<(t}}X
Spgg+;9
} B 8{ uR
jczq`yW
sRq U]i8l
/* Pp*}R2
**FileAccess.java ~@P)tl>
*//文件访问(定位，写) j=ihbR^]Tl
package NetFox; Q2c*.Y
import java.io.*; N9]xJgTze
4ht\&2&:
WZ?!!
public class FileAccessI implements Serializable{ 0H[LS
T~J?AKx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]l[2hy= cV
RandomAccessFile oSavedFile; h|p[OecG
long nPos; R1'`F{56
?N>pZR
e{C6by"j{S
public FileAccessI() throws IOException 2EfflZL3
{ "HC)/)Mv@
this("",0); c7qwNs*f
} [H,u)8)
!8$RBD %
YqU/\f+
public FileAccessI(String sName,long nPos) throws IOException maDz W_3
{ *#2Rvt*Ox
oSavedFile = new RandomAccessFile(sName,"rw"); O,mip
this.nPos = nPos; Of`c`-<j
oSavedFile.seek(nPos); ]k*1KP
} ,4Y*:JU4
[6RfS
0x5xLg;Q
public synchronized int write(byte[] b,int nStart,int nLen) o.^y1mH'
{ 2U9&l1P=
int n = -1; / Z!i;@Wf
try{ El6bD% \G
oSavedFile.write(b,nStart,nLen); V`k8j-*s
n = nLen; r7I B{}>-
} m:{tgcE
catch(IOException e) 9+Nw/eszO
{ irMd jG
e.printStackTrace (); %MJ;Q?KB
} 8#59iQl
d+}kg
(1){A8=?o
return n; 3k'.(P|F
} \L[i9m|e
VPd,]]S5(
n+oDC65[
} <LA^%2jT
( v@jc8y
VJ{pN~_1
/* SI*^f\lu
**SiteInfoBean.java <y>:B}9'
*/ \FifzKA
package NetFox; DJP6TFT&G
{$fsS&aPg
g-@h>$< 1
public class SiteInfoBean { Nl*i5 io
r(`nt-o@
7&6Y
private String sSiteURL; //Site's URL _/ Os^>R
private String sFilePath; //Saved File's Path i&Kz*,pt
private String sFileName; //Saved File's Name $(q8y/,R*-
private int nSplitter; //Count of Splited Downloading File G;]:$J
_N'75
)|]Z>>%t
public SiteInfoBean() )+Y&4Qu
{//nSplitter的缺省值为5 hI~SAd ,#A
//default value of nSplitter is 5 !k<:k "7
this("","","",5); ]rW8y%yD
} 7GZq|M_:y
Z2p> n`D
+t]Xj1Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3s(Ia^
{ v8@eW.I1
sSiteURL= sURL; @Fx@5e
sFilePath = sPath; FA$zZs10\
sFileName = sName; EOVZGZF
this.nSplitter = nSpiltter; k dU! kj
@]'SeiNp
g%\L&}Jd
} qm(1:iK,0
1^{`lK~2
._<ii2K'
public String getSSiteURL() 40K2uT{cq
{ <NB41/
return sSiteURL; xmH-!Da
} \G;CQV#{9
7g6RiH}
59!)j>f
public void setSSiteURL(String value) fLB1)kTS
{ 77We;a
sSiteURL = value; UR3$B%i
} Alz~-hqQ
@{}rG8
3jPB#%F
public String getSFilePath() >oqZ !V5[
{ |9,UaA
return sFilePath; Z> 74.r
} p`>d7S>"
QN G&
*fhX*e8y
public void setSFilePath(String value) _t-7$d"
{ f a5]a
sFilePath = value; OFy,B-`A{
} +1@AGJU3
=A n`D
NWKi ()nA%
public String getSFileName() :ba/W&-d
{ eXzXd*$S
return sFileName; '_o@VO
} *not.2+
V}9;eJRvw
s4t0f_vj`
public void setSFileName(String value) E`AYee%l
{ 3N<&u
sFileName = value; }kPVtSQ
} ;CmOsA,1
!N~*EI$
nem@sB;v#
public int getNSplitter() L[C*@ uK
{ gq4 . d
return nSplitter; dDlG!F_=
} +,_c/(P
mk=#\>
V0NVGRQ
public void setNSplitter(int nCount) Lt>7hBe"
{ fNoR\5}!
nSplitter = nCount; fIyPFqf7w)
} ~@fR[sg<
} $Jf9;.
r/AHJU3&eY
}ND'0*#
/* ")M;+<c"l
**Utility.java ;[Tyt[
*/ \ X$)vK
package NetFox; -P#nT 2
;.s:X
t)I0lnbs
public class Utility { \"d?=uFe
?}sOG?{
o#e7,O
public Utility() j'Wp
{ SE!L :
rJ(OAKnY
7a<_BJXx
} xNgt[fLpS
n`<U"$*
//线程睡眠 (,LL[&;:
public static void sleep(int nSecond) 'F5)ACA%
{ :]c=pH
try{ NG9vml
Thread.sleep(nSecond); d@g2k> >
} #F4X}
catch(Exception e) |s|/]aD}o
{ e2Jp'93o'
e.printStackTrace (); 8^X]z|[d2
} },PBqWe
} UC|JAZL
O71BM@2<
//日志 RgGA$HN/
public static void log(String sMsg) g1qi\axm
{ 8]C1K Zs
System.err.println(sMsg); 7) 0q--B
} 2U%qCfh6|
}n95< {
S=O$JP79
public static void log(int sMsg) Wz{%"o
{ !K\itOEP-
System.err.println(sMsg); 8c).8RLf
} H[BYE
} C*G/_`?9
*Sb2w*c>
fuyl/bx}
/* T.@sq
**TestMethod.java ,?y7,nb
*/ HRHrSf7
package NetFox; D rTM$)
c[{UI
vYzVY\
public class TestMethod { `M rBav
gj;@?o0
if@,vc
public TestMethod() /q*KO\L
{ ///xx/weblogic60b2_win.exe ':sTd^V
try{ {8:o?LnMW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b~as64
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;[~^(. f
SiteFileFetch fileFetch = new SiteFileFetch(bean); xBWx+My
fileFetch.start(); i+AUQ0Zbf6
} [q$e6JwAt
catch(Exception e){e.printStackTrace ();} pqq?*\W&[v
g)cY\`&W8
} J(1V!EA
} ]ymC3LV]
.K7C-Xn=
6Ahr_{
public static void main(String[] args) 7TdQRB
{ 6 [ _fD
new TestMethod(); Ilef+V^qr
} p`p?li
} k<Oy%+C
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