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)); d9"4m>ymS
} $}fA;BP
for(int i=0;i<nEndPos.length-1;i++) ev $eM
{ 5>Q)8`@E
nEndPos = nStartPos[i+1]; ZD(gYNi
} U,BBC
nEndPos[nEndPos.length-1] = nFileLength; 8vK&d>
} J^4k}
} 2wCRT}C
FQ%mNowuj
5FxU=M1gF
//启动子线程 !=:c8V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~A/_\-
for(int i=0;i<nStartPos.length;i++) x#D=?/~/Kv
{ 3 6 ;hg#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {W]jVh p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AK HH{_
nStartPos,nEndPos,i); {QID@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nKdLhCN'=
fileSplitterFetch.start(); Q1z04m1_y[
} b3+PC$z2h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /Ny&;Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +Sfv.6~v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o6 /?WR9
nEndPos = " + nFileLength); Cmj)CJ-
// fileSplitterFetch[nPos.length-1].start(); q@:&^CS
"|if<hx+
3nO|A: t
//等待子线程结束 $$a"A(Y
//int count = 0; tF|bxXsZ
//是否结束while循环 (&(f`c@I
boolean breakWhile = false; <T).+ M/
Cp%|Q.?
EeO{G*pq
while(!bStop) 0*)79Sz
{ U{EW +>
write_nPos(); q<VhP2R
Utility.sleep(500); (P?9Jct
breakWhile = true; `;;!>rm
-g0>>{M'
i(WWF#N5
for(int i=0;i<nStartPos.length;i++) #=rR[:M
{ 7F.,Xvw&@
if(!fileSplitterFetch.bDownOver) s6B@:9
{ ]G:xTv8
breakWhile = false; kbY@Y,:w
break; [C$ 0HW
} 5S1m&s5k
} <CFur
if(breakWhile) W4<}w-AoEp
break; *q RQN+%
)-(NL!?`
o0 Ae*Y0
//count++; G;e}z&6<k
//if(count>4) 5j]%@]M$Z
// siteStop(); (k?OYz]c
} -LyIu#
om1 /9
L$g;^@j
System.err.println("文件下载结束！"); pfT7
} (I$hw"%&
catch(Exception e){e.printStackTrace ();} :O7J9K|
} 6XP>p$-
tVOx
$[Fk>d
//获得文件长度 5M*p1^ >
public long getFileSize() =F9-,"EAI
{ x-1[2K1"[
int nFileLength = -1; ^N]*Zf~N?
try{ oW6.c]Vo
URL url = new URL(siteInfoBean.getSSiteURL()); WCH>9Z>cj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >9 iv>
httpConnection.setRequestProperty("User-Agent","NetFox"); KvQ9R!V
du !.j
"jSn`
int responseCode=httpConnection.getResponseCode(); FB@G.f
if(responseCode>=400) yZ`\.GgC^&
{ (~jOtUyT
processErrorCode(responseCode); WI%,m~
return -2; //-2 represent access is error _/Hu'9432
} -a3C3!!
N$?qAek
YW*ti|u|w
String sHeader; C RNO4
vQ;Z 0_
%]-tA,u
for(int i=1;;i++) t?\osPL
{ {S?.bT%&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W+QI D/
//Utility.log(in.readLine()); DD1S]m
sHeader=httpConnection.getHeaderFieldKey(i); x-[l`k.V
if(sHeader!=null) N67m=wRx
{ FX{Sb"
if(sHeader.equals("Content-Length")) /O9z-!Jz
{ aa|xZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C-8@elZ1
break; `!i>fo~
} <*L8kNykK
} E:2Or~
else NunT1ved
break; Af;$}P
} ="V6z$N
} x`4">:IA
catch(IOException e){e.printStackTrace ();} e.[h
catch(Exception e){e.printStackTrace ();} "h "vp&A
C`fQ` RL\
|q?A8@\u
Utility.log(nFileLength); =vR>KE
IMj{n.y4
;*8$BuD
return nFileLength; i]P]o)
} Na4\)({
0VPa=AW
d2pVO]l YZ
//保存下载信息（文件指针位置） ]c08`
private void write_nPos() v''$qMQ)
{ MZ0 J/@(
try{ ,ecFHkT>
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]\{EUx9
output.writeInt(nStartPos.length); _o;alt
for(int i=0;i<nStartPos.length;i++) L~\Ir
{ j sm{|'
// output.writeLong(nPos); =oBV.BST u
output.writeLong(fileSplitterFetch.nStartPos); E;yP.<PW
output.writeLong(fileSplitterFetch.nEndPos); ig6F!p
} q:fkF^>
output.close(); 8q_nOGd
} `On%1%k8
catch(IOException e){e.printStackTrace ();} :V&#Oo
catch(Exception e){e.printStackTrace ();} -LUKYGBK
} /)j:Y:5
{a(TT)d
$. Ih-
//读取保存的下载信息（文件指针位置） 7"1M3P5*8
private void read_nPos() ^5OR%N)
{ )Zox;}WK+
try{ KrB"2e+J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wtK+\Qnb
int nCount = input.readInt(); ->d3FR
nStartPos = new long[nCount]; svN&~@l
nEndPos = new long[nCount]; y6fYNB
for(int i=0;i<nStartPos.length;i++) @PutUYz
{ <d8Yk>R
nStartPos = input.readLong(); 'bTtdFvJ
nEndPos = input.readLong(); `2G 0B@
} ^)TZHc2a[
input.close(); DKR2b`J
} Yf1?3(0O
catch(IOException e){e.printStackTrace ();} >o.4sN@
catch(Exception e){e.printStackTrace ();} T< D&%)
} ta%yQd7
u{J$]%C
F8nR.|
private void processErrorCode(int nErrorCode) *y0TtEd;
{ 05Ak[OOU>
System.err.println("Error Code : " + nErrorCode); S3$&}I <
} BKi@c\Wb
eot%Th?[
`@RTfBBg
//停止文件下载 _->d41
public void siteStop() EJrP{GH
{ iU+O(vi
bStop = true; xQ%N% `
for(int i=0;i<nStartPos.length;i++) =A{F&:+a]
fileSplitterFetch.splitterStop(); )vn{?Ulj
;ry~x:7L7
Pd)mLs Jg
} XkDIP4v%
} I|(r1.[K
//负责部分文件的抓取 "\3C)Nz?
**FileSplitterFetch.java ~m3Q^ue
*/ yhc}*BMZ
package NetFox; a[I :^S
mb,\wZ
vhvFBx0
import java.io.*; %py3fzg
import java.net.*; T,r?% G{XE
shKTj5s?
$Y,y~4I
public class FileSplitterFetch extends Thread { h/k00hD60
xPCRT*Pd
T\q:
String sURL; //File URL 9eBD)tnw
long nStartPos; //File Snippet Start Position >P@g].Q-
long nEndPos; //File Snippet End Position a5caryZ"z
int nThreadID; //Thread's ID #x*\dL
boolean bDownOver = false; //Downing is over ~bf4_5
boolean bStop = false; //Stop identical H%pD9'q~
FileAccessI fileAccessI = null; //File Access interface 2{|Z?3FJ^
SMonJ;Y
i]9C"Kw$L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {^8?fJ/L
{ w{mw?0
this.sURL = sURL; xu\s2x$
this.nStartPos = nStart; @CMEmgk~
this.nEndPos = nEnd; `3g5n:"g\
nThreadID = id; FRa>cf4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B`|f"+.
} ZmI0|r}QbY
f*}}Az.4
DQ<4`wEM
public void run() nr&bpA/
{ ijP`fM8
while(nStartPos < nEndPos && !bStop) .exBU1Yk@
{ ?zex]!R
>$,P )cB'
>v2/0>U
try{ D%L^[|)c\s
URL url = new URL(sURL); __!LTpp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D6-R>"}
httpConnection.setRequestProperty("User-Agent","NetFox"); P?p]sLrP
String sProperty = "bytes="+nStartPos+"-"; |M`'
httpConnection.setRequestProperty("RANGE",sProperty); I3HO><of
Utility.log(sProperty); )pSA|Qt N
t W+"/<U
$GP66Ev
InputStream input = httpConnection.getInputStream(); 60;_^v
//logResponseHead(httpConnection); eSQkW
}{y)a<`
EHN(K-
byte[] b = new byte[1024]; OClG dFJ|
int nRead; NOg/rDs'{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0<7sM#sI!
{ k4a51[SYBK
nStartPos += fileAccessI.write(b,0,nRead); _3(rwD
//if(nThreadID == 1) !wN2BCSY@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \3OEC`
} Ge_fU'F
+5S>"KAUt0
URceq2_
Utility.log("Thread " + nThreadID + " is over!"); yDfH`]i)U
bDownOver = true; ?7}ybw3t]
//nPos = fileAccessI.write (b,0,nRead); l`.z^+!8@
} D&i\dgbK
catch(Exception e){e.printStackTrace ();} FQJiLb._Z
} %N)B8A9kh
} To}eJ$8*5
Q 9fK)j1$
EB| iW2'
//打印回应的头信息 dP?prT
public void logResponseHead(HttpURLConnection con) M!+J[q
{ ?z`={oN
for(int i=1;;i++) oUwo!n}
{ 3CgID6[Sy
String header=con.getHeaderFieldKey(i); <o/!M6^:
if(header!=null) b{qN7X~>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); SV@*[r
Utility.log(header+" : "+con.getHeaderField(header)); <l(n)|H1P
else MA,*$BgZ
break; ltfKqY-
} <3!Al,!ej@
} )by7[I0v
Tf~eH!~0
iLch3[p%
public void splitterStop() o3V\
{ <Y."()}GeH
bStop = true; o2X95NiH
} :`e#I/,
V1B!5N<
5mQ@&E~#W
} 9wZ?")2
@4hzNi+
g'KxjjYT,
/* ffG<hclk
**FileAccess.java PJiU2Y33
*//文件访问(定位，写) o`QNZN7/}
package NetFox; x(._?5
import java.io.*; w+/`l*
Z/%FQ
/i3JP}
public class FileAccessI implements Serializable{ OL>)SJj5
H.\`(`6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T[ZmD{6l
RandomAccessFile oSavedFile; Rjq Xz6
long nPos; ss[`*89
`mzlOB
M2Jf-2
public FileAccessI() throws IOException Ux7LN@4og
{ Ez;Qo8
this("",0); JD#x+~pb,8
} [EDX@Kdq)
GuO}CQs^W
<Cv(@A->
public FileAccessI(String sName,long nPos) throws IOException HD^#"
{ 6LBdTnzUd
oSavedFile = new RandomAccessFile(sName,"rw"); ao2^3e
this.nPos = nPos; nS04Ha
oSavedFile.seek(nPos); .26mB Xr
} K f/[Edn
~.aR=m\#
W}f)VC;D
public synchronized int write(byte[] b,int nStart,int nLen) nd]SI;<
{ (da`aRVDp
int n = -1; B:Ts_9*
try{ E +_n@t"
oSavedFile.write(b,nStart,nLen); Jqj!k*=/
n = nLen; H:@hCO[a
} zbmC?2$
catch(IOException e) Z+&V >
{ +P^ ;7"H
e.printStackTrace (); @khFk.LBD
} x"{aO6M
SI=$s>1
=0pt-FQ
return n; wAKHD*M)
} f`n4'dG
Z^_qXerjP
!?nbB2,
} q#tUDxf(|
5p (zhfuG
_K o#36.S
/* C`hdj/!A
**SiteInfoBean.java eR$@Q
*/ LH5Z@*0#
package NetFox; }T@=I&g;
&eHRn_st5b
HU'Mi8xxy
public class SiteInfoBean { M76p=*
5EFt0?G
2#>;cn\
private String sSiteURL; //Site's URL ,X.[37
private String sFilePath; //Saved File's Path z:>cQUYl
private String sFileName; //Saved File's Name 2aj1IBnz6/
private int nSplitter; //Count of Splited Downloading File 8:$h&aBI
t(u2%R4<d
=]%JTGdp(
public SiteInfoBean() VBX)xQazU
{//nSplitter的缺省值为5 0~bUW V
//default value of nSplitter is 5 Wef%f]u
this("","","",5); C|V7ZL>W
} ;Z]Wj9iY
ij ?7MP
'XK 'T\m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g&s. 0+
{ PMfW;%I.
sSiteURL= sURL; 4yyw:"
sFilePath = sPath; JT?u[pQ^
sFileName = sName; Dh8ECy5k<*
this.nSplitter = nSpiltter; gQ_<;'m)2
)2&3D"V
tm+*ik=x|
} pey=zR!
G?s9c0f
o;$xN3f,
public String getSSiteURL() 'JOUx_@z
{ ;7'O=%
return sSiteURL; $Zu?Gd?
} Ymz/:
gJQ#j~'
:W.H#@'(
public void setSSiteURL(String value) [Fl_R[o
{ )9hqd
sSiteURL = value; WC#6(H5t$
} V&*IZt&
}u_D{bz
`HX:U3/
public String getSFilePath() duaF?\vv
{ W/qXQORv
return sFilePath; L7$f01*
} g-eJan&]N
5W&L6.J}+
2][9Wp
public void setSFilePath(String value) danPy2
{ rtj/&>
sFilePath = value; 39v Bsc
} QP(0
y98FEG#S}
(VeK7cU
public String getSFileName() ^&qK\m_A
{ ,b*?7R
return sFileName; CD&a_-'z$K
} $94lF~
#_DpiiS,.Q
,Kv6!ib6Q
public void setSFileName(String value) $|~<6A{y
{ uj8saNu
sFileName = value; 287j,'vR
} ^B<-.(F
t\M6 d6
eC-&.Fl
public int getNSplitter() NNt n
{ 90vWqL!
return nSplitter; w!m4>w
} 4|?(LHBD)
1aAOT6h
Qc7*p]E&
public void setNSplitter(int nCount) [+\He/M6
{ 2j-l<!s
nSplitter = nCount; A%^?z.
} ctP+ECH
} vFUp$[
k-~}KlP
f Fi=/}
/* In?rQiD9
**Utility.java ^T&{ORWz
*/ WsHDIp
package NetFox; fEBi'Ad
%r^tZ;;l
.\oz
public class Utility { Ic'D#m
G#%Sokkb'
& DP"RWT/
public Utility() TCp9C1Q4
{ <Y`(J#
A|"T8KSMB
v?He]e'
} jkk%zu
zZMKgFR@
//线程睡眠 O~5t[
public static void sleep(int nSecond) D"4*l5l
{ b$@I(.X:
try{ "09v6Tx
Thread.sleep(nSecond); |b\a)1Po:
} Ce+:9}[
catch(Exception e) mZiKA-t
{ ThV>gn5
e.printStackTrace (); y3;M$Jr
} }1 O"?6
} PJK:LZw
KH2]:&6:Q
//日志 6w%n$tiX
public static void log(String sMsg) `oMZ9Gq2E
{ aj4ZS
System.err.println(sMsg); Xm,fyk>
} g[~{iu_$d
y(DT^>0
2*sTU
public static void log(int sMsg) &<><4MQ
{ M[qhy.
System.err.println(sMsg); ?b7ttlX{
} {J"]tx9 ]
} 2D:/.9= 8v
7)U ik}0
3FvVM0l"
/* Fx!D:.)/G
**TestMethod.java ^x0N]/
*/ 6|=]i-8
package NetFox; k{r<S|PK0
;=joQWNDm
!Ge;f/@
public class TestMethod { T`^Jws{;7
e#hg,I
O1\4WG%
public TestMethod() 5@RcAQb:
{ ///xx/weblogic60b2_win.exe * K$U[$s
try{ *-ys}sX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T @^ S:K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %f<>Kwr`2
SiteFileFetch fileFetch = new SiteFileFetch(bean); !n;3jAl&$
fileFetch.start(); fln[Q2zl
} w7`pbcY,
catch(Exception e){e.printStackTrace ();} S0StC$$1
Ab[o~X"
b"\lF1Nf&o
} 6Gg`ExcT5
1Xi>&;],
sSh." H
public static void main(String[] args) &yP|t":HWX
{ @(c^u;
new TestMethod(); 8AW}7.<5
} v#gXXO[P1
} I:t?#)wl
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