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)); &/uakkS
} U[;ECw@
for(int i=0;i<nEndPos.length-1;i++) exSwx-zxI
{ TuCHD~rb
nEndPos = nStartPos[i+1]; 1c"s+k]9
} @Z$fEG)9
nEndPos[nEndPos.length-1] = nFileLength; p=[dt
} 7Y~5gn
} u*iqwm.
b*|?7
|1ry*~
//启动子线程 (*eX'^Q)d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rA<J^dX=C
for(int i=0;i<nStartPos.length;i++) :FSg%IUX
{ :W&klUU"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GPAC0K^p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vr47PM2al
nStartPos,nEndPos,i); (.oDxs()I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FLPN#1
fileSplitterFetch.start(); Th,]nVsGs~
} E.$//P n|1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @:hWahMy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W{ozZuo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AS0(NlV
nEndPos = " + nFileLength); _kOuD}_|
// fileSplitterFetch[nPos.length-1].start(); i-0AcN./p
T06w`'aL
<5]_u:
//等待子线程结束 4mBM5Tv
//int count = 0; UlN}SddI9
//是否结束while循环 /Y\q&}
boolean breakWhile = false; -{eiV0<^
7je1vNs
T;3~teVYB
while(!bStop) c?xeBC1-
{ vA*NJ%&`
write_nPos(); ZQz;EV!
Utility.sleep(500); {XhpxJ__
breakWhile = true; )}w-;HX
2s 9U&
'uUa|J1mu
for(int i=0;i<nStartPos.length;i++) Jz;`L3m
{ zSsogAx
if(!fileSplitterFetch.bDownOver) *qMjoP,
{ k3OnvnJb
breakWhile = false; &n6 |L8
break; Z+J~moW `
} N9)ERW2`*
} /$vX1T
if(breakWhile) QBoX3w=
break; @J@bD+Q+0
K1<l/ s
N/^[c+J[E
//count++; l%2B4d9"v
//if(count>4) 1d.>?^uE
// siteStop(); wL0"1Ya
} kgmb<4p
jS/$o?
U/(R_U>=
System.err.println("文件下载结束！"); jaux:fU
} dnPr2oI?I
catch(Exception e){e.printStackTrace ();} ~}~ yR*K%
} \BsvUGd
WWTJ%Rd|
yNx"Ey dk`
//获得文件长度 XnvaT(k7Y
public long getFileSize() 8{Svax(
{ I#p-P)Q%S
int nFileLength = -1; )./'RE+(k
try{ A,ao2)
URL url = new URL(siteInfoBean.getSSiteURL()); Q([g1?F9*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v#IZSBvuQK
httpConnection.setRequestProperty("User-Agent","NetFox"); 8>:2li
HoM8V"8B
VxAR,a1+n
int responseCode=httpConnection.getResponseCode(); JY>I
if(responseCode>=400) wIbc8ze
{ uoBPi[nK
processErrorCode(responseCode); ,%m$_wA$
return -2; //-2 represent access is error gD fVY%[Z
} pm;g)p?
7@VR:~n}k
JeCEj=_Z
String sHeader; X_|} b[b
}fxH>79g
-3b0;L&4>x
for(int i=1;;i++) [ 06B)|s
{ r?2C%GI`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X4*/h$48 w
//Utility.log(in.readLine()); *KV]MdS
sHeader=httpConnection.getHeaderFieldKey(i); qm}7w3I^
if(sHeader!=null) 55|$Imnf
{ g(;ejKSR
if(sHeader.equals("Content-Length")) N=L urXv
{ 7~`6~qg.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DFjkp;`1
break; tv|=`~Y
} )ZmE"
} Bp6Evi
else -XY]WWlq
break; ||,;07
} ]X _&
} j({L6</x
catch(IOException e){e.printStackTrace ();} Ap>n4~
catch(Exception e){e.printStackTrace ();} !!K=v7M
,|c_l)
\S2'3SDd/
Utility.log(nFileLength); Wj*6}N/
wy&*6>.
O "h+i>|l
return nFileLength; n:!J3pR
} I2l'y8)d
,wEM
{k]VT4/
//保存下载信息（文件指针位置） `RzM)ILl
private void write_nPos() =XS'V*
{ P?uKDON
try{ V+K.' J ^@
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,[hJi3xM
output.writeInt(nStartPos.length); {DO9{96w4
for(int i=0;i<nStartPos.length;i++) 0UB'6wRVo
{ XKK*RVs#
// output.writeLong(nPos); BR%:`uiQ<
output.writeLong(fileSplitterFetch.nStartPos); E|Lh$9XONA
output.writeLong(fileSplitterFetch.nEndPos); n*xNMw1x"T
} 1-[{4{R
output.close(); (jyJ-qe
} xX>448=
catch(IOException e){e.printStackTrace ();} U)o8Tr
catch(Exception e){e.printStackTrace ();} LOYv%9$0*p
} jH G(d$h
aH#|LrdJ
~gDtj&F
//读取保存的下载信息（文件指针位置） FxT [4
private void read_nPos() V)Xcn'h
{ zj)[Sntn?
try{ DpR%s",Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8ksDXf`.
int nCount = input.readInt(); V!=]a^]:
nStartPos = new long[nCount]; \d;Ow8%d/
nEndPos = new long[nCount]; LMDa68 s
for(int i=0;i<nStartPos.length;i++) 8+W^t I
{ )G|UB8]
nStartPos = input.readLong(); Mt:(w;Y
nEndPos = input.readLong(); `'QPe42
} t8[:}[Jx
input.close(); ZtT`_G&
} pL-$Np] V
catch(IOException e){e.printStackTrace ();} j)5Vv K\
catch(Exception e){e.printStackTrace ();} i xyjl[G
} 1FX-#Y`e
EkBM>*W
mnia>; 0H
private void processErrorCode(int nErrorCode) }?^G=IP4(
{ Z~gqTB]H
System.err.println("Error Code : " + nErrorCode); Mf63 59
} iB`m!g6$
oAx0$]+%V)
YD%Kd&es
//停止文件下载 +Lr0i_al
public void siteStop() N!3f1d7RQ
{ ;vx9xs?6
bStop = true; HTG;'$H^
for(int i=0;i<nStartPos.length;i++) /P%:u0fX,
fileSplitterFetch.splitterStop(); dd+).*
b6(yyYdF
BkF[nL*|
} G~Sfpf
} re*/JkDq3K
//负责部分文件的抓取 ;D7jE+
**FileSplitterFetch.java A!~o?ej
*/ ^pP 14y*go
package NetFox; gs3}rW
A.FI] K@
k|D!0^HE[
import java.io.*; VGq]id{*$
import java.net.*; %Z? o]
2P}RZvUd
#wyS?FP-
public class FileSplitterFetch extends Thread { UTt#ltun?
Id0F2 [
;a`X|N9
String sURL; //File URL ~83P09\T%
long nStartPos; //File Snippet Start Position 1DP)6{x
long nEndPos; //File Snippet End Position yN.D(ZwF:
int nThreadID; //Thread's ID GdU W$.
boolean bDownOver = false; //Downing is over %ab79RS]C
boolean bStop = false; //Stop identical jo*9QO
FileAccessI fileAccessI = null; //File Access interface -G 'lyH
e{,/
mI%/k7:sf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NsHveOK1.
{ QFYy$T+W
this.sURL = sURL; a6d KQ3D
this.nStartPos = nStart; Xn=fLb(
this.nEndPos = nEnd; K;l'IN"N
nThreadID = id; c"ztrKQQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'Ap5Aq
} nmGHJb,$
a5M>1&j/eC
V]}b3Y!(
public void run() Vvj]2V3
{ jlBCu(.,_
while(nStartPos < nEndPos && !bStop) }t'^Au`X
{ fL;p^t u3
h~p}08
jHCKV
try{ rzHa&:Y
URL url = new URL(sURL); Fe.*O`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O@rb4(
httpConnection.setRequestProperty("User-Agent","NetFox"); pg)g&ifKl
String sProperty = "bytes="+nStartPos+"-"; !*gAGt_
httpConnection.setRequestProperty("RANGE",sProperty); >``GDjcJ
Utility.log(sProperty); ,GIqRT4K
|Y11sDa9h
]r6bJ2
InputStream input = httpConnection.getInputStream(); Bl];^W^P
//logResponseHead(httpConnection); mtHz6+
$@)d9u cd
HV.7IyBA^
byte[] b = new byte[1024]; #8jd,I%L
int nRead; 3)a29uc:U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ltR^IiA}
{ (SK5pU
nStartPos += fileAccessI.write(b,0,nRead); ]w>fnew
//if(nThreadID == 1) FF/R_xnx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E,@UM$alP
} df& |Lc1J
[B`P]}gL:
;G]'}$`/q
Utility.log("Thread " + nThreadID + " is over!"); -;$/<
bDownOver = true; =1\wZuK#
//nPos = fileAccessI.write (b,0,nRead); .<%M8rcj
} ud D[hPJd
catch(Exception e){e.printStackTrace ();} 59J9V3na
} UAZ&*{MM^
} hJsC \C,^
4 G[hU4L
Yur)_m
//打印回应的头信息 YPnJldVn
public void logResponseHead(HttpURLConnection con) u0b-JJ7)BQ
{ sEyl\GL
for(int i=1;;i++) S45>f(!
{ 5i#w:O\cz
String header=con.getHeaderFieldKey(i); ^^l"brPa
if(header!=null) h+D=/:B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YWrY{6M
Utility.log(header+" : "+con.getHeaderField(header)); .`N`M9
else 'Y\"^'OU\
break; @98SC}}u
} %)Dd{|c
} UE w3AO
T9-a uK0d
yW?%c#9D
public void splitterStop() \r,.hUp
{ Tpx,41(k
bStop = true; 98'XSL|
} %0]b5u
[_b='/8
}Xv1KX'
} 1iL xXd
}F6b ]
G| oG:
/* }tO<_f))
**FileAccess.java }yDq\5s Q[
*//文件访问(定位，写) {NgY8wQB
package NetFox; gEHfsR=D6
import java.io.*; ArzsZ<\//
d ovwB`5
S@NhEc
public class FileAccessI implements Serializable{ 3MJWCo-[
9= $,]M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =3dbw8I
RandomAccessFile oSavedFile; <|Eby!KXR
long nPos; |S`yXsg
'xoE [0!
@k6}4O?{
public FileAccessI() throws IOException ?9@Af{b t2
{ I} fcFL8
this("",0); {<[tYZmj.
} b:cK>fh0_
~{Rt4o _W
KVpAV$|e
public FileAccessI(String sName,long nPos) throws IOException SLOYlRGCi
{ 9~%]|_(
oSavedFile = new RandomAccessFile(sName,"rw"); PFgjWp"Y
this.nPos = nPos; l'".}6S
oSavedFile.seek(nPos); 42wC."A
} >E ;o"
edk9Qd9
_XNR um4
public synchronized int write(byte[] b,int nStart,int nLen) <sYw%9V
{ 7C7(bg,7^
int n = -1; / !
try{ 0*/ r'
oSavedFile.write(b,nStart,nLen); !_H8Q}a
n = nLen; |SukiXJZF
} f<4q]HCa
catch(IOException e) )X!DCL:16
{ O8~U<'=*
e.printStackTrace (); JX$NEq(
} (g2r\hI
NF(IF.8G
XAxI?y[c
return n; `m;"I
} Q[Sd
@TPgA(5NR
$0S#d@v}
} 4\SBf\ c
) wo2GF
Sb9=$0%\
/* f(s3TLM
**SiteInfoBean.java K-k.=6mS
*/ ],}afa!A
package NetFox; wt=>{JM
E(3+o\w
D)ne *},
public class SiteInfoBean { 6O@ ^`T
m#'rI=}!
Q1I_=fT
private String sSiteURL; //Site's URL *5_8\7d
private String sFilePath; //Saved File's Path y_4krY|Zx
private String sFileName; //Saved File's Name #JR,C -w
private int nSplitter; //Count of Splited Downloading File &c?hJ8"
vWi.[]
Z0 IxYEp
public SiteInfoBean() 8xpYQ<cax
{//nSplitter的缺省值为5 NRuG?^/}d
//default value of nSplitter is 5 #[0\=B-
this("","","",5); BOiz ~h6
} )C01fZhD
L8w76|
E,D:D3O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U>_\
{ ,dj*p,J
sSiteURL= sURL; 6n6VEwYj
sFilePath = sPath; /mBBeg^a
sFileName = sName; BXK::M+
this.nSplitter = nSpiltter; Ril21o! j
&Wz`>qYL*
BUA6(
} n:^"[Le
zhX`~){N6
HMS9y%zl/
public String getSSiteURL() :OQ:@Yk
{ $,QpSK`9i
return sSiteURL; E4v_2Q -w
} #u<oEDQ
51ajE2+X&
,F`KQ )\"
public void setSSiteURL(String value) |`Oa/\U
{ R|)2Dg
sSiteURL = value; 6`4W,
} x#j\"$dla
e9Ul A
Il^\3T+
public String getSFilePath() BvZ^^IUb
{ <`p75B
return sFilePath; APtselC
} *e-ptgO
,y8I)+
<jRFN&"h}
public void setSFilePath(String value) 6mF{ImbRbS
{ +{C9uY)$vf
sFilePath = value; Mi/ &$"=
} ]Ic?:lKN
V^`?8P8d
4$?wD <
public String getSFileName() |:(23O
{ :B*vkwT
return sFileName; =(|xU?OL
} C7jc6(>m
JwI`"$>w
;la#Vf:]
public void setSFileName(String value) s7.p$r
{ FfYd+]+?
sFileName = value; 8R)D! 7[l
} 3m43nJ.~
"'F;lzq
0Y6q$h>4
public int getNSplitter() gP%|:"
{ DD@)z0W
return nSplitter; O+E1M=R6h
} S}m$,<x
1(%>`=R8
@Ge>i5q
public void setNSplitter(int nCount) oxMUW<gYd
{ aW=By)S!Y
nSplitter = nCount; kh<pLI>$h
} yWv<A^C&
} +w k]iH
h5&/hBN
%su}Ru
/* L8bI0a]r"*
**Utility.java {HIR>])o
*/ EREolCASb
package NetFox; +-H}s`
Gq0]m
@@%i(>4Z
public class Utility { 83 i1
Z@uTkqG)
%qS]NC
public Utility() bSrRsgKvT
{ B=Zl&1
lJ:M^.Em0
A[^qq UL'
} jF38kj3O7
c?!YFm
//线程睡眠 /lS+J(I
public static void sleep(int nSecond) kfqpI
{ e~+(7_2
try{ =mHkXHE~:
Thread.sleep(nSecond); E7X!cm/2<
} m/YH^N0
catch(Exception e) >:F,-cx<
{ VG<Hw{ c3r
e.printStackTrace (); @cuD8<\i
} Ka]J^w;a
} $5TepH0D
;m@1Ec@*p
//日志 2SDh0F
public static void log(String sMsg) ~!nLbK2
{ kgbobolA
System.err.println(sMsg); Y{k>*: Ax_
} HYjMNj0
b&lN%+%}
eeW' [
public static void log(int sMsg) LbJtpwz>z
{ 0$eyT-:d
System.err.println(sMsg); ~9JW#HHzn
} |'V DI]p&
} O!+nF]V4f
L@{!r=%_>
lQV|U;~D
/* _ yfdj[Ot`
**TestMethod.java X5uS>V%/
*/ ] vC=.&]
package NetFox; "wA0 LH_
2[Z0I4r
a'@-"qk
public class TestMethod { $uEJn&n7}
Xw7{R
^ckj3Y#;
public TestMethod() )t|^Nuj8
{ ///xx/weblogic60b2_win.exe iD>G!\&
try{ T)WZ_bR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y]C;T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hc-lzYS
SiteFileFetch fileFetch = new SiteFileFetch(bean); /635B*g
fileFetch.start(); 33Ssylno
} #/OUGeJ
catch(Exception e){e.printStackTrace ();} |h5kg<Zgo
I3Lg?bZ
\\=.6cg<K
} 6(>3P
Dn~Z SrJ
f>.4-a?
public static void main(String[] args) `WH[DQ
{ q1YLq(e
new TestMethod(); oi7 3YOB
} j((hqJr
} Y)$52m5rM
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