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)); "H@Fe
} x?gQ\0S<
for(int i=0;i<nEndPos.length-1;i++) *cPN\Iu.W
{ \D ^7Z97
nEndPos = nStartPos[i+1]; ^t7_3%%w
} Gg}t-_M
nEndPos[nEndPos.length-1] = nFileLength; t)KPp|&
} 1S&0
} shD+eHo$
$8=(I2&TW
5e)i!;7Uv
//启动子线程 k}#@8n|b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0xLkyt0
for(int i=0;i<nStartPos.length;i++) 3#B@83C0Z
{ X&/(x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r<v_CFJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JOPTc]
nStartPos,nEndPos,i); F~%|3a$Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0:jsV|5B8
fileSplitterFetch.start(); $@68=
} t Z+0}d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .a5X*M]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); } mgVC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \6U 2-m'
nEndPos = " + nFileLength); 80dSQ"y
// fileSplitterFetch[nPos.length-1].start(); 4^0\dq
`..EQBM
wQ@Zwbx
//等待子线程结束 rYD']%2
//int count = 0; 3Sk5I%
//是否结束while循环 DZ,<Jmg&e*
boolean breakWhile = false; wE)] ah:
%s]U@Ku(a
w' .'Yu6
while(!bStop) Ct-rD79l
{ .vN)A *
write_nPos(); !'+\]eA
Utility.sleep(500); X #&(~1O
breakWhile = true; p!C_:Z5i
QziN]
O}e|P~W
for(int i=0;i<nStartPos.length;i++) KsZ@kTs
{ A{G5Plrh
if(!fileSplitterFetch.bDownOver) =`rppO
{ :PHUsy
breakWhile = false; &t[z
break; `\Uc4lRS
} Z83q-
} &8pCHGmV)
if(breakWhile) [lmHXf@1C
break; MA~|y_V
XYz,NpK
nh _DEPMq
//count++; Gw{Gt]liq
//if(count>4) >lUBt5gU
// siteStop(); &*Q|d*CP
} aeN}hG
{JCSR2BB
`V?x xq\
System.err.println("文件下载结束！"); QCZ,K"y
} R[mH35D/
catch(Exception e){e.printStackTrace ();} <Tj"GVZAEO
} 0X] ekq
Co{MIuL
I!C(K^
//获得文件长度 ;oN{I@}k
public long getFileSize() ]# tGT0
{ 8:3oH!n
int nFileLength = -1; [TiTff&LV
try{ SX1Fyy6 w
URL url = new URL(siteInfoBean.getSSiteURL()); ;o~+2Fir
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P#vv+]/
httpConnection.setRequestProperty("User-Agent","NetFox"); >/*?4
k1QpX@
>oM9~7f
int responseCode=httpConnection.getResponseCode(); ')1}#V/I
if(responseCode>=400) oo$WD6eCR
{ ?3B t;<^
processErrorCode(responseCode); Z9;nC zHm
return -2; //-2 represent access is error e)ZyTuj
} #Tgz,e9
Egjk^:@
cEh0Vh-]
String sHeader; _{2Fx[m%
o2 T/IJP
|p=.Gg=2
for(int i=1;;i++) tF;& x g
{ zd6Qw-D7x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 84hi, S5P
//Utility.log(in.readLine()); ^t/'dfF
sHeader=httpConnection.getHeaderFieldKey(i); M&}oat*
if(sHeader!=null) %z!d4J75
{ WacU@L $A
if(sHeader.equals("Content-Length")) 7(+OsE
{ Eezlx9b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -Fok%iQ'5
break; K[Egwk7
} XEgx#F ;F
} vP87{J*DE1
else 1"4nmw}
break; <g/(wSl
} CL<KBmW7
} =?`y(k4a
catch(IOException e){e.printStackTrace ();} sBuq
catch(Exception e){e.printStackTrace ();} "M5ro$qZ}
r:8]\RU
*k@0:a(>
Utility.log(nFileLength); D<D k1
?V\9,BTb)
D"(3VIglq
return nFileLength; }G,SqpcG
} [-:<z?(n4
5>4A}hSe
23u1nU[0
//保存下载信息（文件指针位置） z7.C\l
private void write_nPos() 0imqj7L
{ 13>3R+o
try{ ^b|Nw:
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4-}A'fTU8
output.writeInt(nStartPos.length); "ZJ1`R=Mj
for(int i=0;i<nStartPos.length;i++) WT ~dA95
{ 2 Zjb/
// output.writeLong(nPos); 9^ *ZH1
output.writeLong(fileSplitterFetch.nStartPos); 1A/c/iC
output.writeLong(fileSplitterFetch.nEndPos); SFk11
} (HV~ '5D
output.close(); 2cX"#."5p
} ?C>VB+X}y
catch(IOException e){e.printStackTrace ();} Sfr\%Buv
catch(Exception e){e.printStackTrace ();} Y5A~iGp8E
} }Cq9{0by?a
+VpE-X=T
T.m)c%]^/
//读取保存的下载信息（文件指针位置） <{z3p:\
private void read_nPos() @|UIV
{ v YmtpKNj%
try{ 5dNf$a0E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eS@!\Hx
int nCount = input.readInt(); s*~jvL
nStartPos = new long[nCount]; <sWcS; x
nEndPos = new long[nCount]; .L(j@I t
for(int i=0;i<nStartPos.length;i++) l^eNZ3:H
{ bmq XP
nStartPos = input.readLong(); 2}#wdJ`
nEndPos = input.readLong(); `Py= ?[cD
} +8vzkfr3It
input.close(); [sY1|eX
} R#Nd|f<
catch(IOException e){e.printStackTrace ();} /%q9hI
catch(Exception e){e.printStackTrace ();} :mtw}H 'F8
} QVRokI`BF
Iv|WeSL.
0*:hm%g
private void processErrorCode(int nErrorCode) .lF\bA|
{ r5qx! >
System.err.println("Error Code : " + nErrorCode); AoOG[to7
} Ho._&az9cT
*I1W+W`G
B[_bJ *
//停止文件下载 Qx,$)|_
public void siteStop() llG#nDe
{ I7z]%Z
bStop = true; Q]g4gj
for(int i=0;i<nStartPos.length;i++) [dF=1E>W_J
fileSplitterFetch.splitterStop(); }:D~yEP
<VxpMF
e%c5OZ3~
} *_K-T#
} ?N?pe}
//负责部分文件的抓取 t-x"(
**FileSplitterFetch.java ST8/ ;S#c
*/ Jx>B %vZ\
package NetFox; H!>oLui
j.N\U#3KK
pfQZ|*>lkb
import java.io.*; Qp.!U~
import java.net.*; Aag)c~D
v*fc5"3eO
/FV6lR!0^
public class FileSplitterFetch extends Thread { Z#:@M[HH{
_ *s
vMdhNOU
String sURL; //File URL 2&K|~~
long nStartPos; //File Snippet Start Position K}/`YDu
long nEndPos; //File Snippet End Position GhQ`{iJM
int nThreadID; //Thread's ID X6*y/KGN
boolean bDownOver = false; //Downing is over e27CbA{_w
boolean bStop = false; //Stop identical c%/&@vs7
FileAccessI fileAccessI = null; //File Access interface PyxN_agf
RYJc>
54cgX)E[x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \lIHC{V\
{ 2LH;d`H[0
this.sURL = sURL; |=}~>!!
this.nStartPos = nStart; ',s7h"
this.nEndPos = nEnd; ?F!J@Xn5
nThreadID = id; 35kbE'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 by<@Zwtf
} !;C(pnE
n]c,0N
iSLf:
public void run() 2co{9LM
{ ayz1i:Q|
while(nStartPos < nEndPos && !bStop) t\d;}@bl
{ ~EkGG .
>,vW
GJfNO-
try{ T\CQ
URL url = new URL(sURL); '^3pF2lIw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ']e4!
httpConnection.setRequestProperty("User-Agent","NetFox"); `|?$; )
String sProperty = "bytes="+nStartPos+"-"; b=\3N3OX
httpConnection.setRequestProperty("RANGE",sProperty); F ) ~pw
Utility.log(sProperty); ]JuB6o_L
>M85xjXP
'6J$X-
InputStream input = httpConnection.getInputStream(); I19F\ L`4
//logResponseHead(httpConnection); bO3KaOC8N
*]?YvY
Y,}43a0A
byte[] b = new byte[1024]; 1RHH<c%2n
int nRead; Xb 1^Oj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &scD)
{ 2dW-WHaM
nStartPos += fileAccessI.write(b,0,nRead); xmd$Jol^
//if(nThreadID == 1) 58U[r)/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I3b-uEHev
} bGO_y]Pc
d0E5;3tQ
:u93yH6~8
Utility.log("Thread " + nThreadID + " is over!"); _Fy:3,(
bDownOver = true; F$p,xFH#
//nPos = fileAccessI.write (b,0,nRead); baGI(Dk
} G=Bj1ss.
catch(Exception e){e.printStackTrace ();} S]@iS[|?
} u)>*U'bM
} k5CIU}H"
W7>_nK+g?
:$d3a"]
//打印回应的头信息 cu|q&
public void logResponseHead(HttpURLConnection con) ]HT>-Ba;{h
{ h0}-1kVT^
for(int i=1;;i++) m':m`,c!
{ $7g(-W
String header=con.getHeaderFieldKey(i); #R|4(HlL
if(header!=null) &_gmQ;%t:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {a%cU[q
Utility.log(header+" : "+con.getHeaderField(header)); ^>uGbhBp
else c~;.m<yrf
break; 3qZ{yr2N[
} >.>5%
} rMloj8O*
u?/]"4
]z NL+]1_
public void splitterStop() V^5 t~)#46
{ 1-<Xi-=^{t
bStop = true; AlV2tffY^
} qIp`'.#m
dq&d>f1
'KG`{K$
} (>23[;.0
E ..[F<5
y0^FTSQ|
/* :#;?dMkTY
**FileAccess.java `dhK$jYD
*//文件访问(定位，写) fRmc_tx
package NetFox; .=S{
import java.io.*; p6*D^-
I&0yUhn
2(|V1]6D?
public class FileAccessI implements Serializable{ ;?9~^,l
u@Lu.t!],
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >LSA?dy!?
RandomAccessFile oSavedFile; !JA63
long nPos; suwj1qYJ4
j!/(9*\
k:.c(_2M
public FileAccessI() throws IOException Sl#XJ0 g
{ 1GxYuTZ{
this("",0); /uVB[Tk^
} .^,vK7
xM,3F jF
ORTM[cL
public FileAccessI(String sName,long nPos) throws IOException tz{]H9
{ a@./e @p
oSavedFile = new RandomAccessFile(sName,"rw"); mB\|<2
this.nPos = nPos; (;h\)B!o
oSavedFile.seek(nPos); xMU)
} xXtDGP
wpvaTHo
Jor?;qo3
public synchronized int write(byte[] b,int nStart,int nLen) .:0nK bW
{ RK0IkRXQd
int n = -1; V/Tp&+Z.c
try{ aw`mB,5U
oSavedFile.write(b,nStart,nLen); 8b/yT4f
n = nLen; -T>`PJpJuL
} @`{UiTNX`
catch(IOException e) Q. >"@c[
{ UcZ3v]$I
e.printStackTrace (); uf6{M_jXZ
} Y9u2:y!LdL
p0/I}n4<5n
VybiuP
return n; l\eq/yg_
} R]dB Uu
X qh+
D_{J:Hb
} {5*5tCIt
q7;)&_'
3^Ex_jeB
/* ~7*HZ:.
**SiteInfoBean.java ,J[sg7vcv
*/ =3@^TW(j
package NetFox; y ^YrGz.
R_lNC]b0
_K8-O>I "
public class SiteInfoBean { IL<5Suz:
:%Bo)0a9
PiN3t]2
private String sSiteURL; //Site's URL 6>l-jTM
private String sFilePath; //Saved File's Path ?p5Eo{B
private String sFileName; //Saved File's Name `jJb) z3D
private int nSplitter; //Count of Splited Downloading File Y$N|p{Z
(T@ov~@
HLS^Ga,(
public SiteInfoBean() %K zURv
{//nSplitter的缺省值为5 bBZvL
//default value of nSplitter is 5 9Y7 tI3
this("","","",5); ALFw[1X
} wc;5tb#
S"lcePN
ioZ2J"s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <)M?qkjb
{ 7n#0eska,
sSiteURL= sURL; R (6Jvub"I
sFilePath = sPath; k(s3~S2h
sFileName = sName; U\51j
this.nSplitter = nSpiltter; &fW;;>
&vLZj
fz:F*zT1
} g|W~0A@D
Bs^W0K$uBO
uu(.,11`
public String getSSiteURL() D@mDhhK_
{ $?0<rvGJ
return sSiteURL; %!WQ;(
} %e3lb<sv6
2f4*r^
Q}G
public void setSSiteURL(String value) gp;(M~we
{ z.7 UfLV9
sSiteURL = value; @T1-0!TM')
} Q7i^VN
X^"95Ic
(R.k.,z
public String getSFilePath() $.v5G>-)3
{ @UD6qA
return sFilePath; ZQ@^(64
} ([s2F%S`@
?"J5~_U.
+i{&"o4}
public void setSFilePath(String value) KWM.b"WnXr
{ b>G!K)MS3
sFilePath = value; DLf6D |"
} Z#d_<e?
M7UVL&_z%
_bFX(~37z?
public String getSFileName() Zb3E-'G+
{ :*Sl\:_X)
return sFileName; RKRk,jRL
} vcqL
jR*1%.Ng
9CW .xX8
public void setSFileName(String value) 1NA>W
{ t4 $cMf
sFileName = value; q^k6.5*"
} ,253'53W)
9tqX77UK
ga0W;Vq&X
public int getNSplitter() , En D3 |
{ N(6|TE2
return nSplitter; 6imDA]5N&
} 3/P2&m
OV^) N
PudwcP{
public void setNSplitter(int nCount) [iB`- dE,
{ cC b'z1
nSplitter = nCount; ,accw}G
} nu|;(ly
} 4ijoAW3A^
ney6N@
Gd%KBb
/* q>?uB4>^
**Utility.java fMP$o3;
*/ tFO86 !ln
package NetFox; vrLI`3n]
Tz:mj
grp1nWAs
public class Utility { "~> # ;x{
58ev (f
%\Z{~(&-v
public Utility() IhhB^E|
{ BRhAL1
_r^Cu.[7
7?Q<kB=f
} eZ8~t/8
i*_T\_=
//线程睡眠 t6W$t
public static void sleep(int nSecond) /n"Ib)M
{ _ )b:F=4j
try{ Wz`MEyj
Thread.sleep(nSecond); "d^hY}Xx
} Tky\W%Ag
catch(Exception e) F]:@?}8R
{ y 4j0nF
e.printStackTrace (); .BuXg<`
} 1\X1G>60m
} dj3}Tjt
&!x!j,nT
//日志 8!(4;fN$j.
public static void log(String sMsg) 7^>UUdk(
{ [7]Kvb2t
System.err.println(sMsg); ^rO3B?_
} @doo2qqIe]
38ChS.(
zZ@]Kq;.s
public static void log(int sMsg) ]@wee08
{ '85@U`e.
System.err.println(sMsg); y9kydu#q
} $k5mI1~
} 65X$k]x
?=}~]A5N
E2+x?Sc+
/* 2Z!%Q}Do
**TestMethod.java f mXU)
*/ {ULyB$\-
package NetFox; aZ"9)RJe
{y-7xg~}
6EfGJq
public class TestMethod { a"ZBSg(
1n|)05p
>U?HXu/TJr
public TestMethod() j5QS/3
{ ///xx/weblogic60b2_win.exe R-CFF
try{ G$FNofQx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MDI[TNYG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ozv:$>v@"
SiteFileFetch fileFetch = new SiteFileFetch(bean); Huzw>
fileFetch.start(); M`^;h:DN^
} DWT4D)C,U
catch(Exception e){e.printStackTrace ();} TNs;#Q
rN* ,U\q
AT.WXP0$A
} 0tV"X
"uK`!{
2\ 3}y(
public static void main(String[] args) LU "e9
{ a:nMW'!
new TestMethod(); QQ*yQ\
} E07g^y"}i
} p<%76H A
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