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)); |dEPy-Xe
} o_Z9\'u
for(int i=0;i<nEndPos.length-1;i++) )nf%S+KV
{ ?" 4X&6xl
nEndPos = nStartPos[i+1]; |Q)mBvvN
} *#>(P
nEndPos[nEndPos.length-1] = nFileLength; '.z7)n
} @2. :fK
} %dnpO|L
r ezp7
[;IEZ/ZX
//启动子线程 Nb:j]U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AJ>E\DK0]
for(int i=0;i<nStartPos.length;i++) c-JXWNz
{ Dksn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Drtg7v{@\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OKm,iIp]
nStartPos,nEndPos,i); ?bM%#x{e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wjq9f;
fileSplitterFetch.start(); ;"IWm<]h;-
} Uv[a ~'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ($`IHKF1.l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _Ycz@Jn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;taZixOH
nEndPos = " + nFileLength); XdThl
// fileSplitterFetch[nPos.length-1].start(); 7#+Ih-&EQ
~Yc~_)hD
M887 Q'HSi
//等待子线程结束 k-3;3Mq
//int count = 0; aNKw.S>
//是否结束while循环 5@1h^wv
boolean breakWhile = false; *JX$5bZsI
&Qda|
]\K?%z
while(!bStop) l=9D!64
{ ]t!v`TH
write_nPos(); <2@t~9
Utility.sleep(500); 6R^F^<<
breakWhile = true; l-W)?d
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for(int i=0;i<nStartPos.length;i++) ^k%+ao
{ Ht+roY
if(!fileSplitterFetch.bDownOver) <w}i
{ lwt,w<E$
breakWhile = false; I`XOvSO
break; -"ZNkC=
} mY"Dw^)
} 6{i0i9Tb
if(breakWhile) `f}ZAX
break; !-T#dU
8*&-u +@%
B/3~[ '
//count++; Y_faqmZ9]
//if(count>4) =>PX~/o
// siteStop(); -SD:G]un
} jA?[*HB
}Y.@:v j
QE"$Lc)
System.err.println("文件下载结束！"); :|k!hG
} hoBFC1
catch(Exception e){e.printStackTrace ();} l+6@,TY1U
} 4J,6cOuW4
M6MxY\uM
mQ}\ptdfV
//获得文件长度 Eyf17
public long getFileSize() 74 ptd,
{ 0P$19TN
int nFileLength = -1; XdIno}pN
try{ 8bMw.u=F
URL url = new URL(siteInfoBean.getSSiteURL()); m8L %!6o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \4$Nx/@Q}
httpConnection.setRequestProperty("User-Agent","NetFox"); 'p[6K'Uq5
l]DRJ
*vBhd2HO
int responseCode=httpConnection.getResponseCode(); o|n;{zT"
if(responseCode>=400) Kc r)W
{ h\#4[/
processErrorCode(responseCode); IuPDr %
return -2; //-2 represent access is error ~hk!N!J\
} |1ry*~
(*eX'^Q)d
moVf(7
String sHeader; #|769=1
;w%g*S
q{*[uJ}Xc"
for(int i=1;;i++) L ~Vw`C
{ V^qBbk%l>D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :/? Op
//Utility.log(in.readLine()); /:A239=+?
sHeader=httpConnection.getHeaderFieldKey(i); gjT`<CW
if(sHeader!=null) oIE(`l0l
{ 2\$<&]q
if(sHeader.equals("Content-Length")) }1CO>a<
{ hHw1<! M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8_>:0(y
break; ;/m>c{
} WR.7%U';
} S WsD]rn
else gDfM}2]/
break; ,9=P=JH
} p(4Ek"
} G@ybx[_[@
catch(IOException e){e.printStackTrace ();} +A,cdi9z
catch(Exception e){e.printStackTrace ();} b2F1^]p
%E,-dw
79Q,XRWh|
Utility.log(nFileLength); {QK9pZB
w\t
Dh{P23}
return nFileLength; ]6=opvm
} g+.E=Ef8<4
~U?vB((j!
e!i.u'z
//保存下载信息（文件指针位置） 3joMtRB>;
private void write_nPos() d9D*w/clMi
{ I GcR5/3
try{ "J >, Hr9
output = new DataOutputStream(new FileOutputStream(tmpFile)); wL0"1Ya
output.writeInt(nStartPos.length); rUiUv(q
for(int i=0;i<nStartPos.length;i++) =g@hh)3wP
{ @izS_I,
// output.writeLong(nPos); H<b4B$/
output.writeLong(fileSplitterFetch.nStartPos); 4f0dc\$
output.writeLong(fileSplitterFetch.nEndPos); \BsvUGd
} WWTJ%Rd|
output.close(); g]}]/\
} 1^;&?E
catch(IOException e){e.printStackTrace ();} <* PjG}Z.
catch(Exception e){e.printStackTrace ();} x~yd/ R
} [qt^gy)
S 1Ji\
1 gRR
//读取保存的下载信息（文件指针位置） .fW`/BXE
private void read_nPos() V|0UwS\n
{ VKrKA71Z~
try{ Z3T26Uk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); / dn]`Ge)
int nCount = input.readInt(); R91u6r#
nStartPos = new long[nCount]; D3 E!jQ1
nEndPos = new long[nCount]; t;ga>^NA"
for(int i=0;i<nStartPos.length;i++) s{j3F
{ zwHTtE
nStartPos = input.readLong(); p/s5[>N
nEndPos = input.readLong(); CV7.hF<
} z!j`Qoh?V9
input.close(); wA)R7%&
} XlNB9\"5
catch(IOException e){e.printStackTrace ();} s*}d`"YvH
catch(Exception e){e.printStackTrace ();} ?at~il$z'
} PsD]gN5"
sAc)X!}
Un[#zh<4
private void processErrorCode(int nErrorCode) &jPsdv h
{ &l|B>{4v
System.err.println("Error Code : " + nErrorCode); r>q`# ~
} 8i"{GGVC
J.`.lQ$z
*XzUqK
//停止文件下载 u09OnP\
public void siteStop() K<_H`k*x
{ ;6)|'3.B9
bStop = true; CnA*o 8w
for(int i=0;i<nStartPos.length;i++) zKWi9
fileSplitterFetch.splitterStop(); S"Zs'7dy`
!8s:3]
khu,P[3>
} CGg6nCB
} D{z=)'/F
//负责部分文件的抓取 qC|re!K
**FileSplitterFetch.java aA yFu_
*/ ->#7_W
package NetFox; &k{@:z
AU$5"kBE
h/w- &7t
import java.io.*; 42Ffx?Qmv
import java.net.*; hQ8{ A7
>\p}UPx
,!py n<_
public class FileSplitterFetch extends Thread { @',;/j80
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ta4<d)nB
String sURL; //File URL /iQ>he~fy
long nStartPos; //File Snippet Start Position yq,5M1vR
long nEndPos; //File Snippet End Position @+!d@`w:z2
int nThreadID; //Thread's ID EX5kF
boolean bDownOver = false; //Downing is over D 7E^;W)H
boolean bStop = false; //Stop identical |)_<JAN
FileAccessI fileAccessI = null; //File Access interface !c`1~a!
jKQP0 t-
XF$C)id2p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LtvyWc`
{ |Z/ySAFM
this.sURL = sURL; wb9zJAsc
this.nStartPos = nStart; J/*[wj
this.nEndPos = nEnd; Z,&ywMm/G
nThreadID = id; 5LK>n-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]-`{kX
} \%VoX`B
g?+P&FL#I
?{dno=
public void run() O&0R ~<n
{ [(K^x?\Y0'
while(nStartPos < nEndPos && !bStop) dk ?0r
{ C|JWom\J
>) ^!gz8
7I
try{ /][U$Q;Ke
URL url = new URL(sURL); ljCgIfZ_4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?0<3"2Db~
httpConnection.setRequestProperty("User-Agent","NetFox"); t|DYz#]
String sProperty = "bytes="+nStartPos+"-"; >y@w-,1he
httpConnection.setRequestProperty("RANGE",sProperty); K&h|r`W(
Utility.log(sProperty); 33C#iR1(WJ
lqs_7HhvRS
;Os3 !
InputStream input = httpConnection.getInputStream(); <Jk|Bmw;
//logResponseHead(httpConnection); i\'N1S<D
g<-cHF
}A;Xd/,'r
byte[] b = new byte[1024]; 334*nQ
int nRead; BMW4E 5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <.2Z{;z
{ RinRQd
nStartPos += fileAccessI.write(b,0,nRead); 3QVng^"B)
//if(nThreadID == 1) kgu+q\?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .PxM #;i2
} _Owz%
nNKL{Hp
3^a"$VW1
Utility.log("Thread " + nThreadID + " is over!"); L$Q+R'
bDownOver = true; 1&<@(S<
//nPos = fileAccessI.write (b,0,nRead); rG]Xgq"
} _V?Q4}7d/
catch(Exception e){e.printStackTrace ();} ( FRf.mv{
} l]Sui_+ZU
} 8K/lpqw
xl^'U/
ZjK~s)RC
//打印回应的头信息 90!Ib~7zH
public void logResponseHead(HttpURLConnection con) Z-?9F`}
{ 3PGyqt(
for(int i=1;;i++) (!(bysi9
{ F*=RP$sj
String header=con.getHeaderFieldKey(i); B+LNDnjO]
if(header!=null) V_kE"W)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sFTIRVXN,
Utility.log(header+" : "+con.getHeaderField(header)); Y(f-e,
else 4Ojw&ys@V
break; U{Z>y?V/
} ^J_hkw~gO
} qr9F
2vC=.1k
2 *$n?
public void splitterStop() K&h6#[^\d
{ ihVQ,Cth
bStop = true; Ah`dt8t
} 4@I]PG
EUkNh>U?
=)8Ct
} (Wqhuw!u
qg/5m;U
gib]#n1!p
/* Q/9b'^UJ
**FileAccess.java [}p.*U_nw
*//文件访问(定位，写) @gc"-V*-/
package NetFox; EoeEg,'~F
import java.io.*; EiUV?Gvz
P$Q&xN<#)
@El<"\
public class FileAccessI implements Serializable{ *@nUas2"
?s]`G'=>V`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JPG!cX%
RandomAccessFile oSavedFile; 4/?Zp4g
long nPos; )QD}R36Ic
`9l\~t(M
$ Zr,-
public FileAccessI() throws IOException ise}> A!t
{ &?6w2[}
this("",0); p/~kw:I
} Cj+=9Dc
M'iKk[Hjfx
~@a R5Q>us
public FileAccessI(String sName,long nPos) throws IOException f,>i%.
{ ex458^N_
oSavedFile = new RandomAccessFile(sName,"rw"); ]o$/xP
this.nPos = nPos; rUjr'O0
oSavedFile.seek(nPos); Pa +BE[z
} ,m,vo_Ub
(xed(uFEK
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public synchronized int write(byte[] b,int nStart,int nLen) _4$DnQ6&
{ (?y2@I}
int n = -1; IcQ!A=lB
try{ 5QJL0fc
oSavedFile.write(b,nStart,nLen); h$\hPLx
n = nLen; qGCg3u6
} [udV }
catch(IOException e) Y +54z/{
{ Ui!|!V-
e.printStackTrace (); gUA}%YXe
} nh)R
`F8;{`a
w.p'Dpw
return n; qhtAtP>i"
} {W<-f?
jqWvLBU!
^6>|!
} ~+yo;[1Yc
wf%Ep#^6}
A>A'dQ69
/* >r3< O=Z7
**SiteInfoBean.java 5Suc#0y
*/ ot#kU 8f
package NetFox; a|uZJ*
f"N3;,Oc
{PtTPz
public class SiteInfoBean { r$Y!Y#hwQ
Ky$G$H
d/rz0L
private String sSiteURL; //Site's URL LW5ggU/
private String sFilePath; //Saved File's Path $]JIA|
private String sFileName; //Saved File's Name Eo&qc 17)`
private int nSplitter; //Count of Splited Downloading File F5P{+z7
\|`Pul$
`+c9m^
public SiteInfoBean() #`0z=w/)
{//nSplitter的缺省值为5 ya g
//default value of nSplitter is 5 TR_oI<xB2
this("","","",5); ItE~MJ5p
} a' o8n6i
}p?V5Qp
Vj`s_IPY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5G;^OI!g
{ WV"QY/e3
sSiteURL= sURL; E=lfg8yb:
sFilePath = sPath; w]o5L
sFileName = sName; _6zP]|VBr
this.nSplitter = nSpiltter; y7EX&
1e&b;l'*=
![ID0}MjJ
} 14!a)Ijl
9k[},MM
@i-@mxk6<
public String getSSiteURL() DeQ'U!?+N
{ %&+R":Bw
return sSiteURL; .0W4Dp
} KVpAV$|e
SLOYlRGCi
9~%]|_(
public void setSSiteURL(String value) PFgjWp"Y
{ l'".}6S
sSiteURL = value; 42wC."A
} >E ;o"
edk9Qd9
_XNR um4
public String getSFilePath() <sYw%9V
{ 7C7(bg,7^
return sFilePath; / !
} 0*/ r'
T^;Jz!e
ss@}Dt^
public void setSFilePath(String value) He-Ja
{ UJ)M:~O
sFilePath = value; O8~U<'=*
} JX$NEq(
\ +-hn
qs1.@l("
public String getSFileName() jsi#l
{ s5aOAyb*w
return sFileName; vJAAAS
} G[<[#$(
Sb9=$0%\
f(s3TLM
public void setSFileName(String value) K-k.=6mS
{ ],}afa!A
sFileName = value; wt=>{JM
} h*%0@
D)ne *},
6O@ ^`T
public int getNSplitter() m#'rI=}!
{ Q1I_=fT
return nSplitter; *5_8\7d
} HZ<f(
~muIi#4
g6/N\[b%
public void setNSplitter(int nCount) vWi.[]
{ Z0 IxYEp
nSplitter = nCount; vV\F^
} -,fa{yt-
} a.&#dxgW[
$X=D9h
ctUF/[_w;
/* g=g.GpFt
**Utility.java +V+*7s%fL
*/ r~G]2*3
package NetFox; h[ZN >T
.m]=JC5'
~UJu @M
public class Utility { <,4R2'
vXM/nw|5
fov=Yd!
public Utility() JGO$4DK-1
{ ogc('HqF^'
ks%7W -
a[74%L?
} ['OCw {<
q'Pz3/mk
//线程睡眠 ^'u;e(AaE
public static void sleep(int nSecond) t3#H@0<
{ F2PLy q
try{ l@Eq|y,
Thread.sleep(nSecond); Q(;B)
} OBw`!G*w
catch(Exception e) _[{:!?-?
{ ,7fc41O3V
e.printStackTrace (); '=Kof1
} C/CfjRzd
} yhtvr5z1
bhqq
//日志 ~ S?-{X+
public static void log(String sMsg) h\u0{!@}
{ qzHqj;
System.err.println(sMsg); .KU SNrs'
} Zu0;/_rN
3b?OW7H
8pq-nuf|K
public static void log(int sMsg) MCi`TXr
{ ^0s\/qyqm
System.err.println(sMsg); J%\~<_2ny
} x'@32gv
} +i`Q 7+d
-#S)}NEn
CEX}`I*-
/* 4g6ksdFQ
**TestMethod.java )pZekh]v
*/ te\h?H
package NetFox; 7dlKdKH
N7~)qqb
rZ!Yi*? f
public class TestMethod { jI{~s]Q
/[20e1 w!
&weY8\HD
public TestMethod() ( *9Ip
{ ///xx/weblogic60b2_win.exe M)`HK .
try{ e:$7^Y,U/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }dd k}wga
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sk7rU+<
SiteFileFetch fileFetch = new SiteFileFetch(bean); uK;K{
fileFetch.start(); |YE,) kiF
} G+hF [b44'
catch(Exception e){e.printStackTrace ();} Q_QKm0!
iBKb/Oi6
0E?s>-b
} SvX=isu!.
{HIR>])o
0~Iu7mPY
public static void main(String[] args) 43J\8WBn@
{ $c@w$2
new TestMethod(); 83 i1
} Z@uTkqG)
} %qS]NC
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