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)); "[ZB+-|[0
} /x p|
for(int i=0;i<nEndPos.length-1;i++) }xh$T'M8
{ :BV6y|J9O^
nEndPos = nStartPos[i+1]; B e0ND2oo
} [UWdW
nEndPos[nEndPos.length-1] = nFileLength; !*B'?|a<\
} )u`[6,d
} ia+oX~W!VR
z?*w8kU&>
7\s"o&G
//启动子线程 ?b>,9A.Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IHv[v*4:
for(int i=0;i<nStartPos.length;i++) )x=1]T>v"'
{ Evg_q>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Eu@huN*/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S(*sw 0O@+
nStartPos,nEndPos,i); %_%Q8,W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #W.#Hjpp
fileSplitterFetch.start(); 2Tp1n8FV
} U!*M*s
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _)>_{Pm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U"^kH|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,N]H dR
nEndPos = " + nFileLength); \=ux atw
// fileSplitterFetch[nPos.length-1].start(); (G;lx
=k^Y?.
po2!
//等待子线程结束 UMm!B`M
//int count = 0; biU^[g("
//是否结束while循环 r\-uJ~8N
boolean breakWhile = false; b((M)Gz
Gsq00j &<Z
2Ay*kmW
while(!bStop) n%o5kVx0
{ >\P@^ h]
write_nPos(); SVh 7zh
Utility.sleep(500); \kMefU
breakWhile = true; %,@e^3B
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afuOeZP
for(int i=0;i<nStartPos.length;i++) deV 8
{ 'mFqEn
if(!fileSplitterFetch.bDownOver) Z8@J`0x
{ xRzFlay8
breakWhile = false; 1q:2\d]
break; 7'W%blg!V
} {byBcG
} J$GUB3 G
if(breakWhile) 1VG4S){}\9
break; Uyg5i[&X@
ZQ%'`q\c
~-_kM
//count++; 2a`o &S
//if(count>4) L\xk:j1[
// siteStop(); kwo3`b
} KyYMfC
#FCnA
Ybs\ES'?A
System.err.println("文件下载结束！"); %7IugHH9y
} p93r'&Q
catch(Exception e){e.printStackTrace ();} T?tgdJ
} #~2%)
7XTkX"zKj
8hOk{xs8
//获得文件长度 NV72
public long getFileSize() irFMmIb
{ ORHp$Un~)
int nFileLength = -1; ?mFv0_!O
try{ ff,pvk8N5
URL url = new URL(siteInfoBean.getSSiteURL()); _VRpI)mu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vt %bI0#
httpConnection.setRequestProperty("User-Agent","NetFox"); \IV1j)I"u
0ghGBuv1s
}Qn&^[[miL
int responseCode=httpConnection.getResponseCode(); (:TjoXXiY
if(responseCode>=400) DEG[Z7Ju
{ .f%fHj
processErrorCode(responseCode); Wz49i9e+d
return -2; //-2 represent access is error [q)8N
} bMg(B-uF7
Ui_8)z _
!;Yg/'vD-
String sHeader; cl=EA6P\X
cl[BF'.H
5\5/
for(int i=1;;i++) Y)0*b5?1r
{ }Jy8.<Gd^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); AS'R?aX|C
//Utility.log(in.readLine()); /YW>*?"N
sHeader=httpConnection.getHeaderFieldKey(i); p*4':TFuD;
if(sHeader!=null) :dl]h&C^
{ C*)3e*T*
if(sHeader.equals("Content-Length")) GP!?^r:en
{ |[<_GQl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U@_dm/;0&
break; EUD~CZhS"k
} ZRh~`yy
} \qdHX
else 0%&1\rm+j
break; l&OKBUG
} y~AVei&
} DBW[{DE
catch(IOException e){e.printStackTrace ();} WejYy|
catch(Exception e){e.printStackTrace ();} w28o}$b`
@=bLDTx;c)
A!s`[2 Z
Utility.log(nFileLength); jSh5!6O
2,$8icM
Cc+t}"^
return nFileLength; "bFTk/
} &gVN&
r?+%?$
H*RC@O_hv
//保存下载信息（文件指针位置） >Ea8G,
private void write_nPos() ~ -4{B
{ 4IB9,?p
try{ p `8s
output = new DataOutputStream(new FileOutputStream(tmpFile)); :1cV;gJ
output.writeInt(nStartPos.length); gn8R[5:!V
for(int i=0;i<nStartPos.length;i++) FcR=v0),
{ T6O::o6
// output.writeLong(nPos); |%F=po>w
output.writeLong(fileSplitterFetch.nStartPos); 3KRd
output.writeLong(fileSplitterFetch.nEndPos); b3&zjjQ
} Y>|B;Kj0(
output.close(); l4D+Y
} ?{P"O!I{
catch(IOException e){e.printStackTrace ();} {C 6=[
catch(Exception e){e.printStackTrace ();} iEVb"w059
} x5,++7Tz
9_# >aOqL
7`-Zuf
//读取保存的下载信息（文件指针位置） 3c#BKHNC
private void read_nPos() %+@O#P
{ @K\~O__
try{ q}`${3qQ3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D"Bl:W'?j
int nCount = input.readInt(); /7aBDc-v
nStartPos = new long[nCount]; =e/9&993
nEndPos = new long[nCount]; s>B5l2Q4
for(int i=0;i<nStartPos.length;i++) j`JMeCG=Ee
{ )IP,;<
nStartPos = input.readLong(); iZ#!O*>
nEndPos = input.readLong(); ]{)a,c NG
} 4,bv)Im+ `
input.close(); Ttu2skcv
} sv: 9clJ
catch(IOException e){e.printStackTrace ();} nno}e/zqf
catch(Exception e){e.printStackTrace ();} hv`~?n)D66
} N|8P)
9v;Vv0k_
Od)Uv1
private void processErrorCode(int nErrorCode) H{@Yo\J
{ #o=y?(
System.err.println("Error Code : " + nErrorCode); b(*!$EB
} s[M?as
a=1NED'
N+m)/x =:
//停止文件下载 nGpXI\K
public void siteStop() T}Km?d
{ xHUsFms
bStop = true; `n#H5Oyn
for(int i=0;i<nStartPos.length;i++) ZOft.P O
fileSplitterFetch.splitterStop(); In:9\7~jC
t9,\Hdo
mPOGidxix
} K{x\4
} ~xA-V4.
//负责部分文件的抓取 @GBxL*e
**FileSplitterFetch.java Sc>,lIM
*/ S'|,oUWDb
package NetFox; ujDd1Bxf?
C\S3Gs
T_i:}ul
import java.io.*; $*SW8'],`
import java.net.*; >sfRI]OG
whmdcVh.
n(b(yXYm]
public class FileSplitterFetch extends Thread { 4~k\j
J4QXz[dG
ta35 K"
String sURL; //File URL DwaBdN[!7
long nStartPos; //File Snippet Start Position LM$W*
long nEndPos; //File Snippet End Position aO]ZZleNS
int nThreadID; //Thread's ID x^HGVWw_
boolean bDownOver = false; //Downing is over =@m &s^R
boolean bStop = false; //Stop identical vX{J' H]u
FileAccessI fileAccessI = null; //File Access interface pf%=h |
$h5xH9x ;
}O/U;4Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =q>'19^Jx
{ VbJiZw(aR
this.sURL = sURL; NhfJ30~
this.nStartPos = nStart; DQNnNsP:M-
this.nEndPos = nEnd; z8jk[5z
nThreadID = id; VO,!x~S!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZRv*!n(Ug<
} TMAJb+@l:
;,$NAejgd
O!zV)^r
public void run() m`IC6*
{ U1@IX4^2`
while(nStartPos < nEndPos && !bStop) {G|,\O1
{ [DJflCR&
s8QMewU
?Y)vGlWDW<
try{ tkVbo.[8K
URL url = new URL(sURL); pA`+hQNN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nA?`BOe(
httpConnection.setRequestProperty("User-Agent","NetFox"); 3!3xCO
String sProperty = "bytes="+nStartPos+"-"; l]@&D#3ZM
httpConnection.setRequestProperty("RANGE",sProperty); x9$` W
Utility.log(sProperty); _.>QEh5"5
2{]`W57_=
aiQ>xen5C5
InputStream input = httpConnection.getInputStream(); YCdS!&^UN
//logResponseHead(httpConnection); !zuxz
K)-U1JE7
ln$&``L
byte[] b = new byte[1024]; 6,"IDH|ND
int nRead; =CK4.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5j:0Yt
{ 4,..kSA3iw
nStartPos += fileAccessI.write(b,0,nRead); ~u)}ScTp
//if(nThreadID == 1) ]p*l%(dhY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V\6=ySx
} VOKZ dC-
p%iGc<vHX
3Dg,GaRk
Utility.log("Thread " + nThreadID + " is over!"); WzAb|&?
bDownOver = true; JCz@s~f\y
//nPos = fileAccessI.write (b,0,nRead); F ;{n"3<
} .EpV;xq}
catch(Exception e){e.printStackTrace ();} Cnnh7`
} ^:6{22C{
} ~oI1zNz/
n/DP>U$I&
N<f"]
//打印回应的头信息 @WJgWJm
public void logResponseHead(HttpURLConnection con) wDcj,:h`
{ vK 7^*qr;j
for(int i=1;;i++) y@ ML/9X8q
{ ykv94i?Q
String header=con.getHeaderFieldKey(i); `o<' x.I
if(header!=null) |B.0TdF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _=+V/=
Utility.log(header+" : "+con.getHeaderField(header)); ,pqGX3
else Ae mDJ8Y
break; J+[_Wd
} "nZ*{uv
} wyp|qIS;
)u3 Zm
0*%Z's\M"
public void splitterStop() iDMJicW!+F
{ :r%P.60H X
bStop = true; nNrPHNfqD
} ~}F{vm
=Qh\D
NXwz$}}Pp
} W4hbK9y
Z&0'a
8'~[pMn`
/* UjaK&K+M?
**FileAccess.java ="x\`+U
*//文件访问(定位，写) xm%Um\Pb7
package NetFox; }xBc0gr
import java.io.*; +lJG(Qd
y|CP;:f;
Xg<*@4RD8
public class FileAccessI implements Serializable{ !xP8#|1
t0z!DOODZP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n.wF&f'D]
RandomAccessFile oSavedFile; XID<(HBA"!
long nPos; j*F`"df
! vP[;6
ELBa}h;
public FileAccessI() throws IOException rrQQZ5fhb
{ 20vXSYa~
this("",0); D!.[q-<
} 350_CN,
Y3r%B9~
%FXfqF9
public FileAccessI(String sName,long nPos) throws IOException A:aE|v/T&
{ /V8}eZ97
oSavedFile = new RandomAccessFile(sName,"rw"); ^dP KDrKxh
this.nPos = nPos; F_Y7@Ei/
oSavedFile.seek(nPos); ZN!4;
} 1"/He ` 4
j{Hao\F8
9;Itqe{8w
public synchronized int write(byte[] b,int nStart,int nLen) G"X8}:}
{ R<sJ^nx
int n = -1; t'BLVCu
try{ (7XCA,KTGI
oSavedFile.write(b,nStart,nLen); _/Gczy4)#
n = nLen; V6t,BJjS
} `kbSu}
catch(IOException e) 6T+FH;h
{ NG
e.printStackTrace (); Mr?Xp(.}G
} j6>.n49_
.u:81I=w(
r) $+
return n; (4'$y`Z
} P`#Z9 HM4
g)s{IAVx
BYs-V:
} f8M$45A'
p!sWYui
`!Ds6
/* CamE'
**SiteInfoBean.java 1QmH{jM
*/ o&`<+4 i
package NetFox; 2WtRJi?b|
F#5B<I
2P/K K
public class SiteInfoBean { c6nflk.l
tjGd )
k$H%.l;E
private String sSiteURL; //Site's URL '~ ,p[
private String sFilePath; //Saved File's Path ][W_[0v
private String sFileName; //Saved File's Name K?s+3
private int nSplitter; //Count of Splited Downloading File FDVcow*]n
9AxCiT.
w=^`w:5X
public SiteInfoBean() w QNxL5B
{//nSplitter的缺省值为5 Bn61AFy`
//default value of nSplitter is 5 ,hq)1u
this("","","",5); ua5OGx
} Kv.>Vf.T}_
wD68tG$
\[gReaI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {?J/c{=/P
{ :4MB]v[K
sSiteURL= sURL; A,%C,*)Cg
sFilePath = sPath; Hir Fl
sFileName = sName; Ga#:P F0
this.nSplitter = nSpiltter; 9cEv&3
aYuD>rD
x~GQV^(l3
} {"&SJt[%X
/1x,h"T\<
'XzXZJ[uq
public String getSSiteURL() ~zSCg|"r
{ @+9<O0
return sSiteURL; %^1cyk
} ,WvY$_#xW%
K_2|_MLlZ
EL8NZ%:v:
public void setSSiteURL(String value) yaG= j
{ .&9 i
sSiteURL = value; dbOdq
} FXzFHU/dP
z I+\Oll#Q
H ,+? t
public String getSFilePath() xdf82)
{ NzU,va N
return sFilePath; qf=1?=l291
} /9zE^YcT
V5GW:QT
Ma8_:7`>O
public void setSFilePath(String value) rg{9UVj
{ {dL?rQ>5L
sFilePath = value; 94 e): jS
} ;x:rZV/
%H]lGN)
X=Ys<TM,
public String getSFileName() q^A+<d
{ 3,]gEE3
return sFileName; RjWqGr;bO
} Wm);C~Le
$KLD2BAL
I!>\#K
public void setSFileName(String value) {X[ HCfJd
{ # eCjn
sFileName = value; *P 3V
} `ORECg)
e"'#\tSG
zGc: @z
public int getNSplitter() ++aL4:
{ )u/H>;L P
return nSplitter; u`olW%C/T
} Q>R>R*1.j
m}8[#:
>~`r:0',
public void setNSplitter(int nCount) I j$lDJS
{ ,_X/Gb6)
nSplitter = nCount; K =wBpLB
} XuD=E
} rHf&:~
+J{0 E
<JV"@H=
/* m8SA6Y\
**Utility.java $&"V^@
*/ Ndo a4L)$
package NetFox; hUD7_arKF
zfc3)7
?UK|>9y}Z
public class Utility { lj{VL}R
o/C\d$i'
{q<03d~9|G
public Utility() zOV=9"~{
{ j:}DBk
H-3Eo#b#
_[Vf547vS
} 6<N5_1
?W(6
//线程睡眠 K]U;?h&CZc
public static void sleep(int nSecond) M.nvB)
{ RGn!{=
try{ kKPi:G52F
Thread.sleep(nSecond); W`"uu.~f
} +uBLk0/)>
catch(Exception e) "wlt> SU
{ f>s?4
e.printStackTrace (); r}0\}~'?c
} $t5V=}m>
} [! 'op0
#U*_1P0h
//日志 `Pw*_2
public static void log(String sMsg) `60gFVu
{ 4;HJ;0-ps
System.err.println(sMsg); MwfOy@|N
} '{[5M!B
w~#nYM=fP!
-tnQCwq#
public static void log(int sMsg) BW"&6t#kA
{ dgDy5{_
System.err.println(sMsg); McoK@q;
} 8)kLV_+%
} gORJWQv
\`ZW* EtPI
]r3Kg12Mi
/* S}f?.7
**TestMethod.java :5/Uh/sX
*/ 2o#,kGd
package NetFox; 4O:W#bx
<$N"q
:QWq"cBem
public class TestMethod { J*l4|^i<
oQv3GpO
\}~s2Y5j
public TestMethod() Y-'78BJk
{ ///xx/weblogic60b2_win.exe 0<PR+Iv*i
try{ }<z_Q_b+e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fK&e7j`qO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @:tj<\G]
SiteFileFetch fileFetch = new SiteFileFetch(bean); G&;j6<hl
fileFetch.start(); be e5
} /T,Z>R
catch(Exception e){e.printStackTrace ();} RUr=fEH
[]0mX70N
/)xlJUq
} QZX~T|Ckv
BS&;n
SxK:]Aw
public static void main(String[] args) \uME+NF
{ +[J/Zw0{
new TestMethod(); EZ.!rh~+
} &20P,8@
} :L_BG)dM
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