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)); m^m=/'<+
} *icaKy3
for(int i=0;i<nEndPos.length-1;i++) n+Conp/
{ 9mv0}I
nEndPos = nStartPos[i+1]; x5pu+-h
} F$1{w"&
nEndPos[nEndPos.length-1] = nFileLength; a_{'I6a*,
} -r_\=<(
} :"Tkl$@,
1=sL[I7<
@|">j#0
//启动子线程 KSEKoHJo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )D'#>!Y
for(int i=0;i<nStartPos.length;i++) be]/ROP>H
{ 3&{6+A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sKR%YK "A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Fs=x+8'M
nStartPos,nEndPos,i); vkR~nIp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !Y7$cU &
fileSplitterFetch.start(); y!R9)=/M
} qxHn+O!h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fl9VokAT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _?'W30Dg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;pOV; q3j
nEndPos = " + nFileLength); "*l{ m2"
// fileSplitterFetch[nPos.length-1].start(); v3t<rv
KU0Ad);e
BI*0JKQu
//等待子线程结束 eLXL5&}`fh
//int count = 0; OkISRj'!U
//是否结束while循环 (f_J @n
boolean breakWhile = false; T<Qa`|5>
|]?W`KN0
8f)pf$v`
while(!bStop) dV'^K%#
{ K]M@t=
write_nPos(); /?XI,#j3kM
Utility.sleep(500); \Zx&J.D
breakWhile = true; EL z5P}L6
Ars*H,9>e
}0@@_Y]CC
for(int i=0;i<nStartPos.length;i++) s?->2gxhx
{ Y+vIU*O
if(!fileSplitterFetch.bDownOver) S# baOO
{ i`];xNR'
breakWhile = false; O<,\tZ'N
break; BBV>QL
} w,R6:*p5
} F9%+7Op^
if(breakWhile) &OXx\}>MW
break; zzo93d
_:5t~29
8)pL0bg
//count++; W7_m,{q
//if(count>4) VnB HQ.C
// siteStop(); ;XjXv'
} _!Tjb^
<Uf`'X\e6
Cd]A1<6s
System.err.println("文件下载结束！"); a&)!zhVP
} gE=9K @
catch(Exception e){e.printStackTrace ();} 8==M{M/eM
} k W 8>VnW
tf8xc
Fi;OZ>;a
//获得文件长度 ru`U/6n
public long getFileSize() 4/mz>eK"
{ Ya!e83-r
int nFileLength = -1; cwtlOg
try{ (0`w.n
URL url = new URL(siteInfoBean.getSSiteURL()); B|$o.$5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vRf$#fBEQ
httpConnection.setRequestProperty("User-Agent","NetFox"); 7w8UnPuM
uW#s;1H.)
s] ;P<
int responseCode=httpConnection.getResponseCode(); D2gyn-]\
if(responseCode>=400) um_J%v6ER
{ y3QS!3I
processErrorCode(responseCode); *f>\X[wN
return -2; //-2 represent access is error Jq?zr]"A
} a'Zw^g
,2 W=/,5A
<&#]|HGc
String sHeader; .q4$)8[Pg
rbIYLVA+V
afD {w*[8
for(int i=1;;i++) 3k(tv U+eC
{ ?K2}<H-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cTRtMk%^
//Utility.log(in.readLine()); QUvSeNSp
sHeader=httpConnection.getHeaderFieldKey(i); %N(>B_t\
if(sHeader!=null) c$BH`" <*
{ HJym|G>%?
if(sHeader.equals("Content-Length")) BtKor6ba
{ XD0a :T)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6Uq;]@k%
break; Zz/p'3?#
} 4(oU88z
} ;~d$OM
else >#l:]T
break; -%%Xx5D
} Sj|tR[SAoD
} EEK!'[<,sE
catch(IOException e){e.printStackTrace ();} XE2rx2k
catch(Exception e){e.printStackTrace ();} .oTS7rYw
t)?K@{ 9
L$sENOm
Utility.log(nFileLength); ) )FLM^dj
&ynAB)
|s(Ih_Zn
return nFileLength; l`A&LQ[
} 4E2/?3D
IhZn
/N<aN9Z<x,
//保存下载信息（文件指针位置） enQW;N1_M
private void write_nPos() "Y^9g/
{ %la1-r~
try{ c?}G;$
output = new DataOutputStream(new FileOutputStream(tmpFile)); +TaxH;
output.writeInt(nStartPos.length); w{2CV\^>5
for(int i=0;i<nStartPos.length;i++) %0/qb0N&
{ kTI5CoXzq
// output.writeLong(nPos); Q3^h
output.writeLong(fileSplitterFetch.nStartPos); `zw%
output.writeLong(fileSplitterFetch.nEndPos); M<NY`7$^
} mf{M-(6'
output.close(); ='4)E6ea?
} /EP zT7
catch(IOException e){e.printStackTrace ();} qz3 Z'
catch(Exception e){e.printStackTrace ();} chKEGosbF
} =jS$piw.
_O'!C!K6
{ gs$pBu
//读取保存的下载信息（文件指针位置） ~x<?Pj
private void read_nPos() xLi3|^q
{ p8)R#QWz9
try{ oaPWeM+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5G(dvM-n
int nCount = input.readInt(); HQ7g0:-^a>
nStartPos = new long[nCount]; |mHf7gCX
nEndPos = new long[nCount]; l:JVt`A4?
for(int i=0;i<nStartPos.length;i++) ;fW~Gb?"
{ yTK3eK
nStartPos = input.readLong(); G}+@C]
nEndPos = input.readLong(); {I$iD
} hwL`9.w
input.close(); |o9`h9i
} u7RlxA:
catch(IOException e){e.printStackTrace ();} sP2Uj
catch(Exception e){e.printStackTrace ();} `sso Wn4
} W}3%BWn
} eHxw+.
o 7tUv"Rs
private void processErrorCode(int nErrorCode) #Ktk["6
{ L97 ~ma
System.err.println("Error Code : " + nErrorCode); :3 Hz!iZM
} 2PRiiL@
d4^x,hzV
=7H\llL4BC
//停止文件下载 _&9P&Zf4
public void siteStop() 6_u!{
{ 7qUg~GJX
bStop = true; 8IxIW0
for(int i=0;i<nStartPos.length;i++) ~xsJML
fileSplitterFetch.splitterStop(); m;>G]Sbe
<Lxp t
=SeQ- H#
} !o?&{"#+
} Xa#.GrH6
//负责部分文件的抓取 AH/o-$C&
**FileSplitterFetch.java cb0rkmO
*/ Ay 4P_>^
package NetFox; !m9hL>5vR
/!?Tv8TPp
;|?_C8
import java.io.*; @{_X@Wv4iV
import java.net.*; AzZhIhWl">
:Rv+Bm
D]}~`SO
public class FileSplitterFetch extends Thread { ^gp]tAf
p3mZw lO
T$R#d&t
String sURL; //File URL `L7^f!
long nStartPos; //File Snippet Start Position f+s)A(?3
long nEndPos; //File Snippet End Position #V]8FW
int nThreadID; //Thread's ID fjy\Q
boolean bDownOver = false; //Downing is over ]u$tKC
boolean bStop = false; //Stop identical W'"?5} (
FileAccessI fileAccessI = null; //File Access interface )uo".n|n~B
eWex/ m
fiA8W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x4wTQ$*1
{ wEX<[#a-
this.sURL = sURL; o -)[{o\
this.nStartPos = nStart; d-e/0F!
this.nEndPos = nEnd; G!I5Er0pdy
nThreadID = id; CdmpKkq#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w+*rbJ
} G/},lUzLg
![r)KE=v8I
0)b1'xt',
public void run() "9aFA(H6w
{ F*Hovxez
while(nStartPos < nEndPos && !bStop) Vjt7X"_/
{ tx9%.)M:n
W5Pur lu?
HpIi-Es7C
try{ &-Wt!X 3
URL url = new URL(sURL); 8N9,HNBT$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lt:&lIW,3
httpConnection.setRequestProperty("User-Agent","NetFox"); N}7b^0k
String sProperty = "bytes="+nStartPos+"-"; 0n`Temb/
httpConnection.setRequestProperty("RANGE",sProperty); u?MhK#Mr
Utility.log(sProperty); Hf_ pe
C6a-
rKslgZhQ
InputStream input = httpConnection.getInputStream(); @}!?}QU
//logResponseHead(httpConnection); -X7x~x-
uaKbqX
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byte[] b = new byte[1024]; Z`GEF|eh
int nRead; bf2n%-&9g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~p n$'1Q
{ MoEh25U.
nStartPos += fileAccessI.write(b,0,nRead); M.MQ?`_"b
//if(nThreadID == 1) Y:m8UnT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z2,NWmP|w
} $yj*n;
w~crj$UM
8?kB+}@6X
Utility.log("Thread " + nThreadID + " is over!"); 1pDU}rPJ.
bDownOver = true; :R:@V#Y
//nPos = fileAccessI.write (b,0,nRead); tK{#kApHGG
} 8,vP']4r%
catch(Exception e){e.printStackTrace ();} fSVM[
} hslT49m>
} lV4TFt,
7SYe:^Dx
d#bg(y\G|
//打印回应的头信息 )T gfd5B
public void logResponseHead(HttpURLConnection con) 7p':a)
{ . a @7
for(int i=1;;i++) mSu$1m8
{ ~~k0&mK|Q
String header=con.getHeaderFieldKey(i); s}` |!Vyl
if(header!=null) cyHbAtl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3PRU
Utility.log(header+" : "+con.getHeaderField(header)); U*sQ5uq
else S\t!7Xs%*U
break; ]|w~{X!b4
} L1Yj9i
} 'w72i/
1'TS!/ll];
!XI9evJw
public void splitterStop() s!D2s2b9e
{ fQ!W)>mi
bStop = true; u0oTqD?
} T>#~.4A0
4,X CbcC
G^SJhdO(Q
} >rP[Xox'
iS.gN&\z^
=+DhLH}8
/* P2s\f;Dwr
**FileAccess.java mA,{E-T
*//文件访问(定位，写) f8r7SFwUv
package NetFox; +/mCYI
import java.io.*; f!5w+6(
@RuMo"js
"o u{bKe
public class FileAccessI implements Serializable{ i-4L{T\K
2MYez>D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lAC"7 Z?F
RandomAccessFile oSavedFile; j^U"GprA
long nPos; tIod=a)
B|9XqQ EI
xmC5uT6L3M
public FileAccessI() throws IOException N z=P1&G'
{ v<l]K$5J&
this("",0); AFYdBK]
} ]S9Z5l0
:-hVbS0I
S-Vxlku]
public FileAccessI(String sName,long nPos) throws IOException =c&.I}^1L
{ FdEUZ[IT`{
oSavedFile = new RandomAccessFile(sName,"rw"); %Q]thv:
this.nPos = nPos; XA.1Y)
oSavedFile.seek(nPos); DXO'MZon3
} \fI05GZ
*L*{FnsV
})(robBkA
public synchronized int write(byte[] b,int nStart,int nLen) !-%%94Q
{ *nHMQ/uf
int n = -1; FoZI0p?L)9
try{ l>s@&%;Mg
oSavedFile.write(b,nStart,nLen); yn(bW\
n = nLen; F,pKt.x
} *u,&?fCl
catch(IOException e) {]m/15/$C
{ BAi0w{
e.printStackTrace (); w6mYLK%
} ZzR0k
`}$bJCSF.n
4sH?85=j
return n; <KCyXU*
} \xC#Zs[<
.Xe_Gp"x
7z/O#Fbs
} 4:b'VHW.
RwrRN+&s\
z?|bs?HKS
/* _;S~nn
**SiteInfoBean.java .i|nn[H &
*/ <~_XT>`y
package NetFox; z_{_wAuY
fF9hL3h?)
%i?v)EW
public class SiteInfoBean { gCVOm-*:
$cm9xW&
F1M:"-bda
private String sSiteURL; //Site's URL .We{W{
private String sFilePath; //Saved File's Path c_.Fe'E
private String sFileName; //Saved File's Name i?eVi
private int nSplitter; //Count of Splited Downloading File %hH> %
Up_"qD6
T;PLUjp}
public SiteInfoBean() A>FWvlLw'm
{//nSplitter的缺省值为5 N Mx:Jh-YN
//default value of nSplitter is 5 Y!Io @{f
this("","","",5); m$pRA0s2`
} [!uVo>Q4
^1_[UG
AqaMi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~>~qA0m"m
{ f3>DmH#
sSiteURL= sURL; n3-VqYUP
sFilePath = sPath; 1O,8=,K2a
sFileName = sName; S>j.i
this.nSplitter = nSpiltter; m] -cRf)9
3r,Kt&2$
V 7ZGT
} <viC~=k;
>XM]UdP
:Y9/} b{
public String getSSiteURL() *_}0vd
{ _bgv +/
return sSiteURL; YGc:84S
} )_4()#3
MtoOIkQ
%@TC- xx
public void setSSiteURL(String value) P6'Se'f8
{ vr2PCG[~
sSiteURL = value; F=#V/ #ia
} |pq9i)e&
_.BT%4
:IfwhI)
public String getSFilePath() SN\c2^#
{ 0O*kC43E_
return sFilePath; p7r/`_'|
} tp&|*M3
A%^7D.j
@tD (<*f+
public void setSFilePath(String value) m_`%#$s}
{ 'lu3BQvfh
sFilePath = value; )Z['=+s%
} _G25$%/LU
E7aG&K
r=54@`O!
public String getSFileName() SR?(z
{ %&V%=-O_7
return sFileName; S)4p'cUwq
} HTvUt*U1
_)~VKA]""
n}(A4^=4KQ
public void setSFileName(String value) K1]3zLnS
{ _jgtZ
sFileName = value; '!,(G3
} DGS,iRLnA
.sFN[>)
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public int getNSplitter() 6h %rt]g
{ wp> z04
return nSplitter; @>V;guJC%
} DZ`m{l3H
YgS,5::SU
RU~ku{8?
public void setNSplitter(int nCount) *yjnC
{ d2-oy5cEB
nSplitter = nCount; mo(>SnS<
} BfVh\lkH
} BpYxH#4
Y~UAE.
Zzz94`
/* <1<xSr
**Utility.java 6DgdS5GhT_
*/ oVPr`]
package NetFox; 4neO$^i8J
Ek6g?rj_
c/v|e&q
public class Utility { o; U!{G(X
J.M&Vj:
uLPBl~Y
public Utility() VfP\)Rl
{ &/"a E
0(:SEiz6s
zR]!g|;f
} vZ.<OD4
x-%RRm<V
//线程睡眠 ftl?x'P%
public static void sleep(int nSecond) M6Np!0G
{ 5$cjCjY
try{ w-LENdw
Thread.sleep(nSecond); :2,NKdD
} \hBzP^*"n
catch(Exception e) ~dpf1fP
{ Qx8(w"k*
e.printStackTrace (); CS(2bj^6D
} p:W]
} .jk A'i@
;e/F( J
//日志 18Z1F
public static void log(String sMsg) kV4Oq.E
{ 3JBXGT0gJ
System.err.println(sMsg); ?# _{h
} nhjT2Sl
C])s'XTs
IOdxMzF`m
public static void log(int sMsg) C1UU v=|
{ ugE!EEy[^
System.err.println(sMsg); ubOXEkZ8N
} 2{vAs
} [Z#Sj=z
5\#I4\
~QxW^DGa7]
/* B%MdJD>
**TestMethod.java pq&[cA_w
*/ K%x]:|,>M
package NetFox; IM/xBP
x-X~'p'f
BI%XF 9{
public class TestMethod { #u8#< ,w
9q_{_%G%
=W:=}ODD
public TestMethod() ?6`B;_m
{ ///xx/weblogic60b2_win.exe kROIVO1|`
try{ mTxqcQc:7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N!3Tg564j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z8JW iRn
SiteFileFetch fileFetch = new SiteFileFetch(bean); F@f4-NR>
fileFetch.start(); -D'XxOI
} Bdb}4X rL
catch(Exception e){e.printStackTrace ();} iRlZWgj4^
~"SQwE|
09jE7g @X}
} LR>s2zu-
!U m9ceK
shH2/.>
public static void main(String[] args) js5VgP`
{ tkr&Fs"t+
new TestMethod(); @*Ry`)T
} :W1?t*z:[
} .'<K$:8@|
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