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)); G1,Ro1
} q=T<^Tk#e
for(int i=0;i<nEndPos.length-1;i++) ^.nwc#
{ ?SBh^/zf
nEndPos = nStartPos[i+1]; 9 Wxq)
} ytg7p5{!i
nEndPos[nEndPos.length-1] = nFileLength; =B1`R%t
} .n?5}s+q
} D86K$IT
~Ay
S^*(ALFPj
//启动子线程 >eTf}#s?S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <t% Ao,"
for(int i=0;i<nStartPos.length;i++) Fj'\v#h
{ Rh5@[cg%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h;&&@5@lM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0;.e#(`-
nStartPos,nEndPos,i); [RroHXdk+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h}Fu"zK
fileSplitterFetch.start(); Yk(NZ3O
} wI|bBfd(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jJiCF,m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g`y/_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eW<!^Aer
nEndPos = " + nFileLength); E;ndw/GZjR
// fileSplitterFetch[nPos.length-1].start(); (\5<GCW-
qg/Y;tGSx
pmE1EDPag
//等待子线程结束 $u/8Rp
//int count = 0; W+fkWq7`Xx
//是否结束while循环 zW|$x<M^
boolean breakWhile = false; LA(f]Xmc
XyN`BDFi
_p3WE9T
while(!bStop) cx,u2~43A&
{ ,i1fv "
write_nPos(); 9 ayH:;
Utility.sleep(500); O% j,:t'"
breakWhile = true; So3,Z'z=
Cf8R2(-4
lk5_s@V l
for(int i=0;i<nStartPos.length;i++) $\=6."R5<
{ w+:+r/!g
if(!fileSplitterFetch.bDownOver) #)IdJ]
{ f?oI'5R41
breakWhile = false; L>|A6S#y8/
break; fh/)di
} wFH(.E0@Q
} XmE_F
if(breakWhile) nJnO/~|
break; *GY,h$Ul
^^W`Lh%9
dW] Ej"W
//count++; "'LOaf$X
//if(count>4) tFb|y+
// siteStop(); k;9#4^4(
} O;.d4pO(tC
I+-Rs2wb
4.$hHFqS^5
System.err.println("文件下载结束！"); |G5=>W
} ?L.p9o-S0
catch(Exception e){e.printStackTrace ();} #oS
} vM$#m1L?
Xqq?S
(rCPr,@0
//获得文件长度 pD)/-Dgdm
public long getFileSize() W"DxIy
{ JN9HT0
int nFileLength = -1; lVO(9sl*i
try{ 0o\=0bH&s
URL url = new URL(siteInfoBean.getSSiteURL()); J0{WqA.P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G/^5P5y%@
httpConnection.setRequestProperty("User-Agent","NetFox"); 'SXpb?CZ
"1\RdTw
/-cX(z 7
int responseCode=httpConnection.getResponseCode(); A*?/F:E
if(responseCode>=400) *PA1iNdKS
{ lqwJ F &
processErrorCode(responseCode); WHh2fN'A5
return -2; //-2 represent access is error UBpM8/U
} (,Zz&3 AV
1[,#@!k@
R _~m\P
String sHeader; YQw/[
`XRb:d^
KfN`ZZ<
for(int i=1;;i++) Yqj.z|}Nb
{ \1c`)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zke~!"iq
//Utility.log(in.readLine()); _*-'yu8#
sHeader=httpConnection.getHeaderFieldKey(i); N*c?Er@8U
if(sHeader!=null) oBGstt@
{ *~MiL9m+?
if(sHeader.equals("Content-Length")) X_Of k
{ EKI+Dq,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qhHRR/p
break; ag*Hs<gi
} Toa#>Z*+Rb
} 0DP%44Cv9
else Aghj)V
break; _s#/f5<:B
} LKwUpu!
} &t@6qi`d
catch(IOException e){e.printStackTrace ();} 8aIq#v
catch(Exception e){e.printStackTrace ();} jL[Is2<@
;Bc<u[G
9h{:!
Utility.log(nFileLength); t+Q|l&|0
r z>zdj5}
Y+5A2Z)f[
return nFileLength; #+5mpDh
} )}g4Rvr
`cTsS
A0 w `o
//保存下载信息（文件指针位置） (2a"W`
private void write_nPos() M#gGD-
{ `E1_S
try{ "Z1&z-
output = new DataOutputStream(new FileOutputStream(tmpFile)); >ehWjL`8
output.writeInt(nStartPos.length); }sN9QgE
for(int i=0;i<nStartPos.length;i++) 0jx~_zq-j
{ fgz'C?
// output.writeLong(nPos); uvc{RP
output.writeLong(fileSplitterFetch.nStartPos); <38@b ]+
output.writeLong(fileSplitterFetch.nEndPos); 7ump:|
} #j~FA3O
output.close(); jH#^O;A
} R5~vmT5W
catch(IOException e){e.printStackTrace ();} ;ZW}47:BS6
catch(Exception e){e.printStackTrace ();} >[3,qP]E
} 88LbO(q\d
OgpH{"
.}u(&
//读取保存的下载信息（文件指针位置） =D:R'0YH
private void read_nPos() 7&S|y]$~
{ )-:f;#xJ
try{ g5YsVp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *,=+R$
int nCount = input.readInt(); q\Io6=39x
nStartPos = new long[nCount]; #;KG6IE
nEndPos = new long[nCount]; Nb,H8;
for(int i=0;i<nStartPos.length;i++) )|1JcnNSa
{ D0_x|a
nStartPos = input.readLong(); g(F*Y>hk
nEndPos = input.readLong(); h],%va[
} ReGb.pf
input.close(); /8-VC"
} 2dlV'U_g
catch(IOException e){e.printStackTrace ();} .KMi)1L)
catch(Exception e){e.printStackTrace ();} 4oEq,o_
} u$ / ]59
jtOsb91c}
Oh85*3
private void processErrorCode(int nErrorCode) UA u4x 7
{ L5P}%1 _
System.err.println("Error Code : " + nErrorCode); w0`L)f5v
} wk7_(gT`0
h+d;`7Z>
g.sV$.T2K
//停止文件下载 ^XB8A=xi
public void siteStop() Zkep7L
{ :[rKSA]@
bStop = true; #$^i x
for(int i=0;i<nStartPos.length;i++) V# %spW
fileSplitterFetch.splitterStop(); 8`?j*FV7kq
&1C9K>
7CN[Z9Y^}
} ZUI\0qh+
} QKkr~?sTO
//负责部分文件的抓取 p?NjxQLA
**FileSplitterFetch.java L/+J|_J)
*/ JF\viMfR
package NetFox; 7%FZXsD
e9~4wt
5WN Z7cO
import java.io.*; ^"#rDP"v
import java.net.*; :NyEd<'
YD.^\E4o
:|mkI#P.
public class FileSplitterFetch extends Thread { ~F6gF7]z
4gNRln-
tLXw&hFk`g
String sURL; //File URL 4'=N{.TtO
long nStartPos; //File Snippet Start Position ._nKM5.
long nEndPos; //File Snippet End Position >o=p5#{
int nThreadID; //Thread's ID EQhV}9
boolean bDownOver = false; //Downing is over #C7j|9Ew1]
boolean bStop = false; //Stop identical CXFAb1m
FileAccessI fileAccessI = null; //File Access interface oVsazYJ|?
e[dRHl
aM}"DY-_ h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vj$6
{ twS3J)UH
this.sURL = sURL; 0qUap*fvC
this.nStartPos = nStart; 1}M.}G2u/
this.nEndPos = nEnd; meD (ja
nThreadID = id; m =F@CA~C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =eLb"7C#0
} OYy !4Fp
'U0I.x(
3pH`]m2
public void run() A:J{
{ Xkm2C)
while(nStartPos < nEndPos && !bStop) -d)n0)9
{ !QspmCo+
dkp[?f)x
-{%''(G
try{ tP{$}cEY
URL url = new URL(sURL); 291|KG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y"%o\DS*
httpConnection.setRequestProperty("User-Agent","NetFox"); \ \}/2#1=c
String sProperty = "bytes="+nStartPos+"-"; `\0a5UFR
httpConnection.setRequestProperty("RANGE",sProperty); K! j*:{
Utility.log(sProperty); qE:DJy<
AAY UXY!
Z!eq/
InputStream input = httpConnection.getInputStream(); cN>i3}fq
//logResponseHead(httpConnection); =Q/>g6
I*2rS_i[T
#L$ I%L"
byte[] b = new byte[1024]; xB+H7Ya
int nRead; [wG%@0\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ljON_*
{ hyoZh Y
nStartPos += fileAccessI.write(b,0,nRead); `{_PSzM
//if(nThreadID == 1) 34:EpZO@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0M98y!A 5^
} a $%[!vF
uy:=V}p
<J`xCm K
Utility.log("Thread " + nThreadID + " is over!"); elB 8
bDownOver = true; Zw{tuO7}K
//nPos = fileAccessI.write (b,0,nRead); ;BVhkWA
} (*BW/.Fq
catch(Exception e){e.printStackTrace ();} =7,UqMl_
} /vMyf),2
} XCriZ|s
3~la/$?p0
b15qy?`y
//打印回应的头信息 j #YFwX4.
public void logResponseHead(HttpURLConnection con) J@iN':l-
{ 4pT|r6!<
for(int i=1;;i++) ;#j82
{ ]l%.X7M9
String header=con.getHeaderFieldKey(i); qQvb;jO
if(header!=null) -rlX<(pl)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -`EoTXT*U
Utility.log(header+" : "+con.getHeaderField(header)); cvfAa#tq>
else p]eD@3Wz
break; V+z)B+
} AoeW<}MO
} &N0|tn
v2sU$M
a6P.Zf7
public void splitterStop() 7`!( 8
{ qKC*jDW
bStop = true; NkI:
} $:wM'&M
![^h<Om
hM w`e
} o+TZUMm
c"1d#8J
@D=`iG%
/* 7d)' y
**FileAccess.java eUlb6{!y?
*//文件访问(定位，写) W<o0Z OO
package NetFox; qH"a!
import java.io.*; -+|[0hpw
v1)6")8o+
{E|gV9g
public class FileAccessI implements Serializable{ +~O{ UGB=
LP /4e`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fM.|#eLi
RandomAccessFile oSavedFile; A!yLwkc:5
long nPos; ze)K-6SKH
{fD#=
v19`7qgR(
public FileAccessI() throws IOException 2zu~#qU[)M
{ d 4R+gIA
this("",0); e~?]F0/
} J7o?h9
Xs@ ^D,
5V!XD9P'
public FileAccessI(String sName,long nPos) throws IOException 12dW:#[
{ |"v{RC0
oSavedFile = new RandomAccessFile(sName,"rw"); :`1g{8.+
this.nPos = nPos; eCD,[At/
oSavedFile.seek(nPos); HC,@tfS
} [bJnl>A
G[j79o
]M;! ])b$
public synchronized int write(byte[] b,int nStart,int nLen) 7:'>~>'
{ c F]3gM
int n = -1; =lQ[%&
try{ 5AU3s
oSavedFile.write(b,nStart,nLen); bz]O(`
n = nLen; oW6<7>1M7
} !H\GHA'DO]
catch(IOException e) .+h pxZ
{ Qpf]3
e.printStackTrace (); kH-b!
} 0u2uYiE-l
yVzg<%CR^
:G/]rDtd
return n; 4+,Z'J%\[7
} T]-~?;Jh8
[)vwg`]
Cq;d2u0)o$
} J?fh3RW9
ygt)7f5
>]8.xkQq
/* 5N<v'6&=
**SiteInfoBean.java Z"Ni Y
*/ i]%"s_l
package NetFox; olxP`iK
Nn1^#kc
RGI6W{\
public class SiteInfoBean { F6VIH(
\ZZy`/~z*7
@$Kq<P
private String sSiteURL; //Site's URL o{W]mr3D
private String sFilePath; //Saved File's Path FH`&C*/F0Y
private String sFileName; //Saved File's Name ?I#hrv@
private int nSplitter; //Count of Splited Downloading File WPKTX,k
@6'E8NFl
#2ASzCe
public SiteInfoBean() '$-,;vnP0
{//nSplitter的缺省值为5 pY#EXZ#
//default value of nSplitter is 5 ;XQ lj?:
this("","","",5); z}&C(m:al
} BM~niW;k
^T6!z^g1h
FD+PD:cQn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TFDCo_>o
{ }h h^U^ia
sSiteURL= sURL; [=3tAPpzK
sFilePath = sPath; pF+wHMhUe
sFileName = sName; +J8/,d
this.nSplitter = nSpiltter; 9$@ g;?}Ps
q%Jy>IXt
yUwgRj
} bTp2)a^G
a;(zH*/XK
JMlhBh
public String getSSiteURL() \[I .
{ %kFELtx
return sSiteURL; - :z5m+
} 4@iJ|l
kS#DKo
q)xl$*g
public void setSSiteURL(String value) v|2q2bz
{ m{dyVE
sSiteURL = value; (jMAa%
} Cf=q_\0|W
E816YS='
_s-HlE?C
public String getSFilePath() 5po'(r|U
{ e0WSHg=6@
return sFilePath; |aAWWd5
} =C>`}%XT}
zQ %z"tQ
2*wO5v
public void setSFilePath(String value) >fA@tUQB
{ \"`>-v"h
sFilePath = value; UAXF64w{
} `pd
7e{X$'
SA+%c)j29
public String getSFileName() L[Yp\[#-q
{ {F+M&+``
return sFileName; s?x>Yl %
} 'BdmFKy1
oT (:33$
0mD;.1:
public void setSFileName(String value) hi D7tb=g~
{ m|2]lb
sFileName = value; $< K)fbG
} hN:F8r+DG
5ZyBP~
Zjic"E1
public int getNSplitter() UQ.D!q
{ [q+e]kD
return nSplitter; H@2"ove-uC
} j_'rhEdLP
@f5@0A\0
:&0yf;>v
public void setNSplitter(int nCount) :{i$2\DH6
{ bqQO E4;
nSplitter = nCount; {.3
} @Gn?8Ur%
} VXc+Wm*W
j*La,iF
9oz(=R
/* NBqV0>vR
**Utility.java gAr`hXO
*/ |;.Pj3)-
package NetFox; q 5v?`c
*)`kx
:m++ iR
public class Utility { TcKvSdr'
`zzKD2y
FSU%?PxO
public Utility() gF,[u
{ !&a;P,_Fb
-q&7J' N
.qIy7_^
} 6_%]\37_Z
2l)9Lz=;L
//线程睡眠 7edPH3
public static void sleep(int nSecond) KM6N'x^z
{ Y1fy2\<'
try{ @k+%y'Y?
Thread.sleep(nSecond); 4P4 Fo1
} Q$fRi[/L
catch(Exception e) *TM;trfz
{ ksu}+i,a
e.printStackTrace (); #6N+5Yx_[
} `*" H/QG
} (zs4#ja2,
p2Dh3)&
//日志 <g3du~
public static void log(String sMsg) rQcRjh+E H
{ mWli}j#
System.err.println(sMsg); ~&DB!6*
} a/QtJwIV
/UpD$,T|^|
~MhgAC
public static void log(int sMsg) 2JiAd*WK
{ !EX?m }7
System.err.println(sMsg); QY~<~<d+G
} U/X|i /
} ePq13!FC/
cebs.sF:
gV"qV
/* `dv}a-Q)c
**TestMethod.java /ojO>Y[<
*/ Sa;<B:|
package NetFox; t;.^K\S4
@K$VV^wp
%@lV-(5q
public class TestMethod { Lj&1K~U
n5Nan
:!JpP R5
public TestMethod() _{LN{iqDv
{ ///xx/weblogic60b2_win.exe yn/?= ?0
try{ I*A0?{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'yPCZ`5H(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c=A(o
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9Fy\t{ks
fileFetch.start(); ""1#bs{n
} bBUbw*DF)
catch(Exception e){e.printStackTrace ();} lAdDu
1B)Y;hg6&
7P<r`,~k-
} w]>"'o{{
8K\'Z
tZaD${
public static void main(String[] args) {OB-J\7Y
{ +}_Pf{MW
new TestMethod(); J [ YtA
} |SGgy|/a#
} (Wd_G-da
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