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)); eXU;UO^
} DT=!
for(int i=0;i<nEndPos.length-1;i++) YJ5;a\QxN
{ a`w)awb
nEndPos = nStartPos[i+1]; Kup-O u,
} /rNY;qXM
nEndPos[nEndPos.length-1] = nFileLength; !HXdUAKu
} QsmG(1=
} L#e|t0'#
.~5cNu'#m
K6,5C0
//启动子线程 Oed&B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7#,+Q(2
for(int i=0;i<nStartPos.length;i++) (WW,]#^
{ a<V=C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S)"5X)mq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |7zm!^t$
nStartPos,nEndPos,i); Oh:SH|=]#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F|V co]"S1
fileSplitterFetch.start(); OD"eB?
} 55oLj.l^j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KG#|Cq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iR#jBqXD
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,gU9ywg
nEndPos = " + nFileLength); ?.A6HrAPB
// fileSplitterFetch[nPos.length-1].start(); 'ce9v@(0
utwh"E&W
<,0&Ox
//等待子线程结束 tS2lex%
//int count = 0; 8IC((
//是否结束while循环 >t8eVMMa
boolean breakWhile = false; r/Pg,si
+V|]:{3W
7$GP#V1r/
while(!bStop) @fpxGMy&
{ "`:#sF9S
write_nPos(); qc\o>$-:`
Utility.sleep(500); PyHE>C%
breakWhile = true; !*%3um
!9o8v0ZI
)K2n!Fbd
for(int i=0;i<nStartPos.length;i++) gr=ke #
{ hJ:Hv.{`)W
if(!fileSplitterFetch.bDownOver) p,D/ Pb8
{ yB.6U56
breakWhile = false; McnP>n
break; m$J'nA
} rI]:| k
} )KRO=~Y
if(breakWhile) o7 !@WOeZ3
break; l!iB -?'u
kd\yHI9A
Mdwh-Cis/
//count++; lQ+-g#`
//if(count>4) >5 5/@+^
// siteStop(); Q)a*bPz
} *rEW@06^\
iCx'`^HnP
Q}2w~Cn\S
System.err.println("文件下载结束！"); f\(Kou$
} jv0e&rt
catch(Exception e){e.printStackTrace ();} >8NQ8i=]V1
} >Ft jrEB
`ZefSmb
0XozYyq
//获得文件长度 V,M8RYOnC!
public long getFileSize() _F3vC#
{ Ar'5kPzY>
int nFileLength = -1; GV[[[fu
try{ d&'6l"${
URL url = new URL(siteInfoBean.getSSiteURL()); @pkozE-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &(.ZHF
httpConnection.setRequestProperty("User-Agent","NetFox"); ;5=pBP.
<bTa88,)
Vr0RdO
int responseCode=httpConnection.getResponseCode(); x@k9]6/zs
if(responseCode>=400) b`:Eo+p
{ *pWswcV/
processErrorCode(responseCode); !E7/:t4
return -2; //-2 represent access is error Ta[}k/zW
} d#z67Nl6
"{0kg'fU
ng 6G<hi
String sHeader; TOuFFR
W4YC5ZH{l
"1#,d#Q$
for(int i=1;;i++) 1%=,J'AH
{ Aqm0|GlJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L"b5P2{c
//Utility.log(in.readLine()); ?4~lA L1
sHeader=httpConnection.getHeaderFieldKey(i); Kc{wv/6}T
if(sHeader!=null) T@S+5(
{ n+i}>3'A
if(sHeader.equals("Content-Length")) H5aUZ=
{ _88~uYG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `H|g~7KD&
break; I%s/h4x^B[
} E|fPI u
} G37_ `C
else . }1!MK5
break; BW*zj=N%
} }gn0bCJy
} <=`@`rm{
catch(IOException e){e.printStackTrace ();} F%|(pHk
catch(Exception e){e.printStackTrace ();} kR_[p._
PRUGUHY
C eg6o&^
Utility.log(nFileLength); u@|yw)
#\M<6n{
EagI)W!s[
return nFileLength; fAm2ls7c
} lk'RWy"pw
=Vv{td
& 3a+6!L[
//保存下载信息（文件指针位置） l%:_#1?isf
private void write_nPos() >pYgF=J
{ /za,&7sf
try{ ]Lh\[@#1f
output = new DataOutputStream(new FileOutputStream(tmpFile)); WgL!@g
output.writeInt(nStartPos.length); NdZ: 7
for(int i=0;i<nStartPos.length;i++) r9U1O@c
{ 9PBmBP~
// output.writeLong(nPos); a|>MueJ
output.writeLong(fileSplitterFetch.nStartPos); AuCVpDH
output.writeLong(fileSplitterFetch.nEndPos); aqN.5'2\
} >w'6ZDA*X
output.close(); n#R!`*[
} Ea !j-Lbo
catch(IOException e){e.printStackTrace ();} St3~Y{aI|
catch(Exception e){e.printStackTrace ();} G@;aqe[dB
} p[$I{F*a
Z~R i%XG
O//e0?]W
//读取保存的下载信息（文件指针位置） #-`lLI:w0
private void read_nPos() WZr~Pb9
{ KXGs'D
try{ g=%&p?1@E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1Li@O[%X<
int nCount = input.readInt(); v$cD!`+k
nStartPos = new long[nCount]; ;Cy@TzO/|
nEndPos = new long[nCount]; 3m^BYr*y^
for(int i=0;i<nStartPos.length;i++) 'ZDclz9}
{ L9.#/%I\
nStartPos = input.readLong(); C+mU_g>
nEndPos = input.readLong(); I5~DC
} o?3R HP47
input.close(); DjKjEZHgM
} Z*)<E)
catch(IOException e){e.printStackTrace ();} bODl q
catch(Exception e){e.printStackTrace ();} uu:)jxi
} y{N9.H2
p%s D>1k
JjmL6(*ui
private void processErrorCode(int nErrorCode) ymzm x$o=
{ S;NXOsSu
System.err.println("Error Code : " + nErrorCode); 3%} Ma,
} cm]]9z_<
A>?fbY2n
oxzNV&D[{`
//停止文件下载 bm4W,
public void siteStop() 1mX*0>
{ 1 W0;YcT]
bStop = true; x6t;=
for(int i=0;i<nStartPos.length;i++) |^F-.Z
fileSplitterFetch.splitterStop(); GXfVjC31z
qkIU>b,B
$o/>wgQY-
} @2mP
} &0g,Xkr
//负责部分文件的抓取 ]VvJ1Xn0
**FileSplitterFetch.java 1@WGbORc*
*/ c;^J!e
package NetFox; ^Toi_
ff#-USK^R
>=V+X"\Z
import java.io.*; ZwMw g t
import java.net.*; <-F"&LI{<
pV7Gh`<y
P5>CSWy%
public class FileSplitterFetch extends Thread { TI>yi ^}
tX251S
1 XG-O
String sURL; //File URL {UcItLjY
long nStartPos; //File Snippet Start Position Ps7%:|K]
long nEndPos; //File Snippet End Position =CoT{LRQ_
int nThreadID; //Thread's ID L,6Y=?
boolean bDownOver = false; //Downing is over HhL%iy1
boolean bStop = false; //Stop identical |=LkV"_v
FileAccessI fileAccessI = null; //File Access interface FT~^$)8=
4i,SiFKB
aW"!bAdx`,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zjA/Z(
{ qj&)w9RLJE
this.sURL = sURL; jO55<s94
this.nStartPos = nStart; +!vRU`
this.nEndPos = nEnd; M2}<gRL*}J
nThreadID = id; ZhsZywM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Nj0)/)<r+
} aJ8pJ{,P
rg,63r
>v[(w1?rX
public void run() ^mi4q[PM
{ A-5+#
while(nStartPos < nEndPos && !bStop) +&OqJAu
{ !qlGt)G3
mB{{o}'<u
5F"?]'*/
try{ Z+"&{g
URL url = new URL(sURL); vi8~j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^>Y%L(>
httpConnection.setRequestProperty("User-Agent","NetFox"); &r%*_pX
String sProperty = "bytes="+nStartPos+"-"; 7g)3\C
httpConnection.setRequestProperty("RANGE",sProperty); QCR-lxO1
Utility.log(sProperty); +,Az\aT/%
$VWzv4^:
0>iFXw:fn
InputStream input = httpConnection.getInputStream(); 3J T3;O
//logResponseHead(httpConnection); U[b;#Y1X
_m],(J=,z
bSf(DSqx
byte[] b = new byte[1024]; |lxy< C4V
int nRead; |a{]P=<q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `fZD%o3l
{ 2HXKz7da
nStartPos += fileAccessI.write(b,0,nRead); 9Yyg}l:
//if(nThreadID == 1) aLi_Hrb9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N;'HR)
} gE&W6z0fJ
hXm}d\
,dx)rZ*
Utility.log("Thread " + nThreadID + " is over!"); m>ycN
bDownOver = true; s&hA
//nPos = fileAccessI.write (b,0,nRead); S |>$0P4W(
} P/Kit?kngS
catch(Exception e){e.printStackTrace ();} hFMst%:y$
} </gp3WQ.
} AwUc{h l<
\oX8/-0f
R:<@+z^A[
//打印回应的头信息 PuCDsojclh
public void logResponseHead(HttpURLConnection con) 4|N\Q=,
{ o^Ysp&#p
for(int i=1;;i++) vQ"s
{ `8;,&<U'`
String header=con.getHeaderFieldKey(i); hF"g91P
if(header!=null) QO{=Wi-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !y-2#
Utility.log(header+" : "+con.getHeaderField(header)); 4;RCPC
else "F$o!Vk
break; [fi'=Cb
} `uh@iD'KI
} cEc,eq|
F,M"/hnPT
P4j8`}&/
public void splitterStop() ,6;xr'[o*
{ }b+QYSt
bStop = true; #we>75l{+R
} vo ;F;
RR!!hY3 K
]<T8ZA_Y;
} l(,;wAH
;{f??G
ZuvPDW%
/* EB5_;
**FileAccess.java Hpi%9SAM
*//文件访问(定位，写) `n`"g<K)Q
package NetFox; 'd#\7J>d
import java.io.*; _/}Hqh
;Q=GJ5`B
1N9<d,
public class FileAccessI implements Serializable{ u:$x6/t
j-YJ."
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a4(?]ND~6
RandomAccessFile oSavedFile; ]}[Yf
long nPos; q|o|/O-{
Y/,$Y]%g
b"M`@';+
public FileAccessI() throws IOException eh:}X}c=J]
{ *Z`XG_s5
this("",0); eKVALUw
} w,Zx5bBg%
0<@KDlF
jD/7/G*
public FileAccessI(String sName,long nPos) throws IOException XDkS ^9
{ M6]0Y@@>
oSavedFile = new RandomAccessFile(sName,"rw"); 6W;?8Z_1
this.nPos = nPos; bugFl>
oSavedFile.seek(nPos); %,,`N I{
} ;wXY3|@
3XwU6M$5g
^'&iYV
public synchronized int write(byte[] b,int nStart,int nLen) =r@gJw:B
{ a1G9wC:e
int n = -1; *i?rJH
try{ |vfujzRZ
oSavedFile.write(b,nStart,nLen); +z|UpI
n = nLen; jefNiEE[
} r|^lt7\
catch(IOException e) 8nIMZV
{ ^+.t-3|U
e.printStackTrace (); OyJsz]b} M
} .3a:n\tY
.6#cDrK
],\sRQbv&
return n; IAP/G5'Q
} C[xJU6z
1t~FW-:
[O7w =
} {b'}:aMc
hG3m7ht
A{z>D`d
/* sK@Y!oF}\
**SiteInfoBean.java _k_>aG23
*/ 4YDT%_h0
package NetFox; }UKgF.
WVS$O99Y
LBmM{Gu
public class SiteInfoBean { cX%:
(@)2PO/
q]"2hLq
private String sSiteURL; //Site's URL D[89*@v
private String sFilePath; //Saved File's Path ZT) !8
private String sFileName; //Saved File's Name Cf0|Z
private int nSplitter; //Count of Splited Downloading File *$i;o3
HKTeqH_:
7q%|4Z-~
public SiteInfoBean() ^^7L"je]g
{//nSplitter的缺省值为5 euV$2Fg
//default value of nSplitter is 5 @s%X
this("","","",5); i}PK$sa#c
} L#`2.nU
EI1W .V>@
[)#u<lZ<~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /Jxq 3D)v
{ m$fQ`XzU
sSiteURL= sURL; h@*lWi2K7
sFilePath = sPath; qDnCn H
sFileName = sName; *.,"N}
this.nSplitter = nSpiltter; O87"[c`>
{ p1lae
v:rD3=M-
} 6exI_3A4jh
<nDNiM#
}#yU'#|d
public String getSSiteURL() C=N!z
{ "^;#f+0
return sSiteURL; P<%v+O
} -xJX_6}A
iv:,fkwG
{(rf/:X!p
public void setSSiteURL(String value) X*pZNz&E
{ T/[f5?p
sSiteURL = value; 7\IL
} j~Q}F|i8
A LXUaE.
Q |
public String getSFilePath() b,#`n
{ 8y$5oD6g9
return sFilePath; m</]D WJ
} }>2t&+v+
gaQ[3g
NW z9C=y
public void setSFilePath(String value) N0+hejz
{ b-PSm=`
sFilePath = value; j!YNg*H
} O!;H}{[dg
\B_i$<Sz
zhNQuK,L
public String getSFileName() ?-e7e%
{ SOVjEo4'3
return sFileName; }N?g|
} wHx}U M"
:^n*V6.4
'X9AG6K1
public void setSFileName(String value) lM>.@:
{ :-z&Y492
sFileName = value; K[kds`
} H4t)+(:D'
Zr=ib
70_}S*T
public int getNSplitter() ^f9>l;Lb
{ p"2m90IO
return nSplitter; Cl,9yU)1n
} elu=9d];@
0; 7#ji
`|nH1sHFq
public void setNSplitter(int nCount) `%e|$pK
{ ;AKwx|I$g
nSplitter = nCount; Hb+X}7c$
} E Zi&]
} G~"z_ (
u$C\E<G^
h\(B#SN
/* 6 Ew@L<v
**Utility.java RT,:hH
*/ a"x}b
package NetFox; bl=ku<}@
GMl"{Oxo&
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public class Utility { (~JwLe@a
rvwa!YY}
["u#{>(X
public Utility() Lbcy:E*g
{ Zae.MO^C!
uQnT[\k?
H9U.lb
} {Ur7#h5
@Gt`Ds9=
//线程睡眠 V@[rf<,
public static void sleep(int nSecond) m^<p8KZ
{ :5J_5,?;`
try{ p}uncIod
Thread.sleep(nSecond); pr_>b`p6
} 28a$NP\KW
catch(Exception e) sf$o(^P9\A
{ #AShbl jm+
e.printStackTrace (); \Wr,<Y
} }9^@5!qX
} wjrG7*_Y4v
M%I@<~wl
//日志 Xwt`(h[u
public static void log(String sMsg) M*w'1fT
{ Jd_;@(Eg=
System.err.println(sMsg); ,!Q]q^{C:W
} Huc|6~X
)hBE11,PB
cLG6(<L
public static void log(int sMsg) rh66_eV
{ E;9>ePd@
System.err.println(sMsg); k[%aCGo
} lNz]HiD
} 6Z?Su(s(5
RbEKP(uw
3#c3IZ-;
/* YHB9mZi
**TestMethod.java 1'JD=
*/ r{_>ldjq
package NetFox; E8ta|D
nn+_TMu
zU&L.+
public class TestMethod { {e"dm5
(5a1P;_Y
.t=
public TestMethod() ; b*i3*!g
{ ///xx/weblogic60b2_win.exe Y%@hbUc}x9
try{ eVJ^\z:4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @}&_Dvf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ml0*1Dw
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z.1> kZ
fileFetch.start(); 6@V~0DG
} v7,$7@$:\
catch(Exception e){e.printStackTrace ();} XogVpkA
MjD75hIZ
l$XPIC~H
} Rko M~`CT
XKS8K4"
2'] KTHm
public static void main(String[] args) <CZgQ\Mt
{ , jU5|2
new TestMethod(); e2cP *J
} 6;iJ*2f5V
} `XKVr
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