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)); /5a;_
} tjzA)/T,4
for(int i=0;i<nEndPos.length-1;i++) }OKL z.5
{ hTS|_5b
nEndPos = nStartPos[i+1]; '"O&J}s;
} T&}Ye\%
nEndPos[nEndPos.length-1] = nFileLength; p]f&mBO*
} 9`X&,S~e
} N=fz/CD)I
-q2MrJ*
$ad&#q7
//启动子线程 mZoD033H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h)B!LAr
for(int i=0;i<nStartPos.length;i++) CyTFb$Z
{ )mD\d|7f
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pDDG_4E>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !RMS+Mm?
nStartPos,nEndPos,i); _ VKgs]Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); edN8-P(
fileSplitterFetch.start(); z-Hkz
} (&Q)EBdm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H1UL.g%d=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z`xyb>$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !A-;NGxE
nEndPos = " + nFileLength); QWhp:]}
// fileSplitterFetch[nPos.length-1].start(); uB+9dQ
S:97B\u`
D0%FELG05
//等待子线程结束 *,jqE9:O
//int count = 0; 5Bj77?Z
//是否结束while循环 MSB%{7'o
boolean breakWhile = false; x-~-nn\O
pI^=B-7
nZW4}~0j
while(!bStop) >\\5"Sf
{ Vu|dV\N0*
write_nPos(); 7+8bL{
Utility.sleep(500); XARSGAuw
breakWhile = true; a-Y6w5
w|G~Il
)kA2vX^=Z
for(int i=0;i<nStartPos.length;i++) 59MR|Jt
{ cju@W]!
if(!fileSplitterFetch.bDownOver) \]a uSO
{ PJwEA
breakWhile = false; .HDebi
break; "o==4?*L
} =tq7z =k
} E3tj/4:L
if(breakWhile) '}zT1F* p=
break; *^6k[3VY
nOuN|q=C
2mOfsn d@
//count++; AO8:|?3S
//if(count>4) Tg\hx>
// siteStop(); P%jkKE?B4
} [Yoa"K
Ltg-w\?]
7 s-`QdWX
System.err.println("文件下载结束！"); y[p6y[r*
} 'Z$jBL
catch(Exception e){e.printStackTrace ();} }wG|%Y#+r
} "S|(4BUJ(
~FNPD'`t
]TfeBX6ST
//获得文件长度 ;>/ipnx
public long getFileSize() /MqP[*L
{ w*2^/zh
int nFileLength = -1; +DxifXtB
try{ *vXDuhQ
URL url = new URL(siteInfoBean.getSSiteURL()); }{#7Z8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <tU :U<ea]
httpConnection.setRequestProperty("User-Agent","NetFox"); C&FN#B
ZU^Q1}</5
KMe.i'
int responseCode=httpConnection.getResponseCode(); , Z4p0M
if(responseCode>=400) !r2}59J
{ =_pmy>_z
processErrorCode(responseCode); .Wh6(LDY(
return -2; //-2 represent access is error |WUA1g
} dc)wu]
J;"nm3[.q
\|Y{jG<cu
String sHeader; +E)e1:8
`^`9{@~
2}>go^#O/w
for(int i=1;;i++) }o{!}g9
{ L:Ed-=|Uw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TA<hj[-8
//Utility.log(in.readLine()); y8}"DfU.
sHeader=httpConnection.getHeaderFieldKey(i); MsSoX9A{D
if(sHeader!=null) +:b(%|
{ LP8o7%sv!
if(sHeader.equals("Content-Length")) ;7)OSGR
{ AV9:O{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P)4x
break; 89ZDOji?O
} i"KL;t[1
} AwA1&mh
else )m)h/_
break; JJ)y2
} K"G(?<>~4c
} f};!m=b
catch(IOException e){e.printStackTrace ();} #<D@3ScC
catch(Exception e){e.printStackTrace ();} US"2O!u
rg"TJ"Q-
J~fuW?a]r
Utility.log(nFileLength); 5=Zp%[#
L>i<dD{
0>8ZN!@K
return nFileLength; :R{x]sv
} u;QH8LK
4$qNcMdz
%L{
//保存下载信息（文件指针位置） ]kzv8#
private void write_nPos() hw7~i
{ Cd$dnHVh
try{ P~n8EO1r
output = new DataOutputStream(new FileOutputStream(tmpFile)); CuF%[9[cT
output.writeInt(nStartPos.length); ,,zd.9n
for(int i=0;i<nStartPos.length;i++) (cu'
{ !7ph,/P$7
// output.writeLong(nPos); C8!8u?k
output.writeLong(fileSplitterFetch.nStartPos); f&+XPd %
output.writeLong(fileSplitterFetch.nEndPos); BJ_+z gf`
} p3{x<AO/
output.close(); ]L[JS^#7
} PjiNu.>2(
catch(IOException e){e.printStackTrace ();} dw'<"+zO
catch(Exception e){e.printStackTrace ();} |C&%S"*+D
} U#OWUZ
,s\x]bh
Qo]vpp^[#
//读取保存的下载信息（文件指针位置） Xv`2hf
private void read_nPos() XPGL3[w\V
{ BLWA!-
try{ |Gf1^8:C9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tCd{G c
int nCount = input.readInt(); 5@GD} oAn6
nStartPos = new long[nCount]; 3w[<cq.!
nEndPos = new long[nCount]; wpAw/-/
for(int i=0;i<nStartPos.length;i++) LuQ"E4;nY%
{ pE$|2v
nStartPos = input.readLong(); >_|Z{:z]d.
nEndPos = input.readLong(); Q$/V)0
} ]J8KCjq@
input.close(); ey'pm\Z
} 82G lbd)
catch(IOException e){e.printStackTrace ();} >DPds~k
catch(Exception e){e.printStackTrace ();} V:nMo2'hb
} H={O13
!C9ps]6
rTWh(8T
private void processErrorCode(int nErrorCode) YlZYS'_
{ 7F>gj
System.err.println("Error Code : " + nErrorCode); H9oXZSm
} #i}#jMT
/k4^&
'7S!6kd?
//停止文件下载 34/]m/2NZK
public void siteStop() lBizC5t!o
{ (=S"Kvb~#
bStop = true; ^KaqvG$ed
for(int i=0;i<nStartPos.length;i++) z v L>(R
fileSplitterFetch.splitterStop(); 12%z3/i
h(+m<J
~`nm<
} =;'ope(?S
} F[o+p|nF
//负责部分文件的抓取 &hSnB~hi
**FileSplitterFetch.java 2)HxW}o
*/ 1NE!=;VOl
package NetFox; q\\8b{~
tEpIyC
1kz9>;Ud6
import java.io.*; #;qFPj- v
import java.net.*; XwHu:v'=
7 K;'7
P3,Z5|)
public class FileSplitterFetch extends Thread { X~IRpzC
[[/ }1%
wHBHkz
String sURL; //File URL CrRQPgl+u
long nStartPos; //File Snippet Start Position 60U{ e}Mkb
long nEndPos; //File Snippet End Position $ uz1
int nThreadID; //Thread's ID +l[Z2mW
boolean bDownOver = false; //Downing is over i5L+8kx4
boolean bStop = false; //Stop identical ,T,B0
FileAccessI fileAccessI = null; //File Access interface >q} !>k$B
Z=e[ !c
41 c^\1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mK7^:(<.LO
{ }(f.uN_v
this.sURL = sURL; gLXvw]
this.nStartPos = nStart; !9e\O5PmO
this.nEndPos = nEnd; '0])7jq
nThreadID = id; Q5`+eQ?_\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eCPKpVhP
} %+t
m<,y-bQ*(
jFJW3az@z
public void run() ?:{0
{ mCC:}n"#
while(nStartPos < nEndPos && !bStop) "2vNkO##
{ =hOj8;2
A/Fs?m{7U
yPzULO4
try{ I9Edw]
URL url = new URL(sURL); FJn~ =hA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Sug~FV?k$e
httpConnection.setRequestProperty("User-Agent","NetFox"); 8zWBXV
String sProperty = "bytes="+nStartPos+"-"; ?C#F?N0
httpConnection.setRequestProperty("RANGE",sProperty); cW~6@&zp
Utility.log(sProperty); ]$?zT`>(F
m"?'hR2
\U<F\i
InputStream input = httpConnection.getInputStream(); k Nf!j
//logResponseHead(httpConnection); W=;(t
Un8#f+odR
)LMBxyS
byte[] b = new byte[1024]; f/IRO33
int nRead; =@ L5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'EH
{ Gg3?2h"d
nStartPos += fileAccessI.write(b,0,nRead); ~'Qpf 8)
//if(nThreadID == 1) ^%4( %68
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5wE !_ng>|
} &ESR1$)'P
@LkW_
![X.%
Utility.log("Thread " + nThreadID + " is over!"); ]Nd'%M
bDownOver = true; tx|"v|&e2
//nPos = fileAccessI.write (b,0,nRead); mAYr<=
} )z4kP09
catch(Exception e){e.printStackTrace ();} !5' 8a5
} I")"s
} @$b+~X)7
um_M}t{
:+gCO!9Y
//打印回应的头信息 q*<J$PI
public void logResponseHead(HttpURLConnection con) MSYLkQ}_b
{ eqUn8<<s
for(int i=1;;i++) ?:;hTY
{ fAY2V%Rft
String header=con.getHeaderFieldKey(i); 8^f[-^%
if(header!=null) pn_gq~5ng
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :[X}.]"
Utility.log(header+" : "+con.getHeaderField(header)); iK6<^,]'
else z}b U\3!
break; zOdasEd8!
} /O(;~1B
} 1vR#FE?
QF.wtMGF&
CgTQGJ}-
public void splitterStop() )8N)Z~h
{ %f3Nml
bStop = true; E{k%d39>
} L[[H&#\
A0N ;VYv
~_l:b
} 0or6_y6
h?pGw1Q
2sd=G'7!
/* b09#+CH?
**FileAccess.java |\r\i&|g1
*//文件访问(定位，写) L+0N@`nRF
package NetFox; l<)JAT;P
import java.io.*; (m =u;L"o
$Bwvw)(%
`v/tf|v6
public class FileAccessI implements Serializable{ eQ)ioY
)V+Dqh,-g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :EldP,s#x%
RandomAccessFile oSavedFile; ,9l!fT?iH
long nPos; '$L= sH5
C7*Yg$`{
B=RKi\K6a
public FileAccessI() throws IOException J<P/w%i2
{ @1qUC"Mg
this("",0); t"74HZO>
} *}WqYqOow
a~N)qYL:
=B{$U~}
public FileAccessI(String sName,long nPos) throws IOException 5A=xFj{
{ !E>3N:
oSavedFile = new RandomAccessFile(sName,"rw"); "F.J>QBd
this.nPos = nPos; O9 Au =
oSavedFile.seek(nPos); HIp {< M3
} GPhwq n{
[r< Y0|l,m
V{aIhH>P
public synchronized int write(byte[] b,int nStart,int nLen) }y=n#%|i.
{ >5@ 0lYhH
int n = -1; I8pxo7(-
try{ o _,$`nEJ
oSavedFile.write(b,nStart,nLen); H&K)q5~
n = nLen; 1p5q}">z
} 93p9?4;n-
catch(IOException e) RkXLE"G'
{ !\|@{UJk/
e.printStackTrace (); FUv)<rK
} $YO]IK$
%^@0tT
Fb4S/_ V
return n; -){^ Q:u
} d5W[A#}
I:2jwAl
Q]koj!mMl
} U?m?8vhR6(
_@3O`
5<ya;iK
/* C g,w6<7
**SiteInfoBean.java %RF
*/ BOcEL%+
package NetFox; )UU6\2^
&(U=O?r7
;og<eK
public class SiteInfoBean { n#AH@`&i
Vh-h{
)t 7HioQ
private String sSiteURL; //Site's URL I Y-5/
private String sFilePath; //Saved File's Path :95_W/l
private String sFileName; //Saved File's Name -8J@r2\
private int nSplitter; //Count of Splited Downloading File "%iR-s_>
nLLHggNAV
C4d1*IQk
public SiteInfoBean() OpX
{//nSplitter的缺省值为5 ~CTRPH
//default value of nSplitter is 5 w5G34[v
this("","","",5); =|zyi|
} +?eAaC7s
s5|)4Zac
8{^GC(W{]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Yy;1N{dbT
{ WQ`P^5e
sSiteURL= sURL; Z"&ODVP
sFilePath = sPath; wx7>0[zE
sFileName = sName; KD<`-b)7<
this.nSplitter = nSpiltter; 8pKPbi;(2
!LSWg:Ev+
24k}~"We
} p+1B6j
H0Xda.Y(
pNme jz:
public String getSSiteURL() E$fy*enON
{ {.'g!{SHp
return sSiteURL; lk'jBl%
} Zl/+HU~
z>#$#:Z4
Ppn ZlGQ6
public void setSSiteURL(String value) E)SOcM)
{ d`*vJ#$>2
sSiteURL = value; ApB'O;5
} Z.f<6<gF
J\},o|WI
({62GWnn_
public String getSFilePath() 4p g(QeR
{ _E-GHj>k z
return sFilePath; : .eS|
} *J-jr8&
N^j''siB
z@LP9+?dE
public void setSFilePath(String value) #.K&]OV/88
{ PltPIu)F
sFilePath = value; Xc<9[@
} Cf 8-%
J8[Xl.
C_&tOt
public String getSFileName() NWcF9z%@
{ D'=`O6pK
return sFileName; 3Sb%]f5(
} r!=VV!XZ
g9`ytWmM
#_5+kBA+>'
public void setSFileName(String value) !kYmrj**
{ 'Pn`V{a
sFileName = value; W#/Ol59
} +1A<kJ
.h }D%Qa
cA^7}}?e
public int getNSplitter() XBBRB<l)
{ TMs\#
return nSplitter; [r~lO@
} \p|!=H@
T{Q&}`D)r
;<Q_4 V
public void setNSplitter(int nCount) @J)vuGS
{ &0blHDMj{#
nSplitter = nCount; (6aZQ`H
} uSbg*OA
} }gt~{9?c
,4UJ|D=J
>l[N]CQ
/* rGO3
**Utility.java kE|#mI[>
*/ ot6Pq}
package NetFox; J)+eEmrU
+d15a%^`
~-zC8._w3r
public class Utility { b s*Z{R
(/BkwbJyE
Ke!O^zP92
public Utility() D~,R@7
{ T9.gs}B0
n*uZ=M_/Q
w, wt<@}
} WNi<|A#T{
#pK)
//线程睡眠 Uh}yHD`K
public static void sleep(int nSecond) W>49,A,q
{ XsCbA8Qv
try{ YEj U3^@
Thread.sleep(nSecond); LdL\B0^l
} djp(s$:{4
catch(Exception e) V19*~v=u
{ cke[SUH,
e.printStackTrace (); Hs` '](
} HBu>BSv:
} )}8%Gs4C
r~t7Z+PXF
//日志 W_EN4p~J
public static void log(String sMsg) )$i3j 1[;
{ }8e%s;C
System.err.println(sMsg); lX7^LB
} &3. 8i%
:'=C/AL
i=UJ*c
public static void log(int sMsg) T@XiG:b7
{ D%btlw?{
System.err.println(sMsg); wOP}SMn
} l@ K<p
} 9p<l}h7g
??;[`_h{bz
8a{gEZT,
/* 6P8X)3CE<T
**TestMethod.java o\#e7Hqbh
*/ a{=~#u8
package NetFox; 6]*qx5m`<l
}"v"^5
>XN&QVE
public class TestMethod { j3U8@tuG
x$*OglaS
aMWNZv
public TestMethod() P[~a'u
{ ///xx/weblogic60b2_win.exe MaM7u:kD#
try{ {s]eXc]K}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gB#t"s)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jLg4_N1SD
SiteFileFetch fileFetch = new SiteFileFetch(bean); G.8ZISN/
fileFetch.start(); 4!wfh)Z
} Wj0([n
catch(Exception e){e.printStackTrace ();} 4k8 @u
UF tTt`N2
XR(kR{yo
} Y`v&YcX;
%!RQ:?=
lDzVc`c
public static void main(String[] args) c3+vtP&
{ j.sf FS
new TestMethod(); !xSGZD=AD
} n&^Rs)%v
} ek<U2C_u#
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