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)); (sL!nRw
} #*x8)6Ct
for(int i=0;i<nEndPos.length-1;i++) jZP~!q
{ [@`Ki
nEndPos = nStartPos[i+1]; Q4QF_um
} YLFM3IaP
nEndPos[nEndPos.length-1] = nFileLength; [FN4_
} ;ep@ )Y
} wH0Ks5
Nk@ag)
N9X`81)t
//启动子线程 |!\5nix3A>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z3(:a'
for(int i=0;i<nStartPos.length;i++) ,R5z`O
{ )&wJ_(z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *?s"~XVs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0)nY- f0
nStartPos,nEndPos,i); xI,7ld~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^K`Vqo
fileSplitterFetch.start(); %xhA2
} 6qq{JbK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :?J0e4.]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,e!9WKJ B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {aVL3QU
nEndPos = " + nFileLength); k!= jO#)Rd
// fileSplitterFetch[nPos.length-1].start(); 5#hsy;q;[
jgd^{!
2kV{|`1
//等待子线程结束 bbAJ5EqL
//int count = 0; j hrpS
//是否结束while循环 ns`njx}C
boolean breakWhile = false; <OA[u-ph%S
e'L$g-;>4b
sB'Z9
while(!bStop) &#DKB#.2
{ PR;A 0
write_nPos(); )]P%=
Utility.sleep(500); 4}MZB*);0
breakWhile = true; 2%gLq
VVVw\|JB>
PDtLJt$
for(int i=0;i<nStartPos.length;i++) J'4V_Kjg-
{ e!.r- v9
if(!fileSplitterFetch.bDownOver) NkL>ru!b9
{ J~(M%] &k^
breakWhile = false; x9B5@2J1
break; V{+5Fas^l
} iIO_d4Z
} rWnZIt"
if(breakWhile) U1~6o"1H
break; ua HB\Uc
gaa;PX
R@Bnrk
//count++; MaQ`7U5 |e
//if(count>4) v''F\V )
// siteStop(); /FW{>N1
} U5pg<xI
d>r_a9 .u
#Y;tobB
System.err.println("文件下载结束！"); ?VP07 dQTe
} 2/M:KR
catch(Exception e){e.printStackTrace ();} ~ $QNp#dq
} HI*j6H?\
VT~jgsY
~LufHbr
//获得文件长度 =BNS3W6
public long getFileSize() [7*$Sd
{ <Z58"dg.5
int nFileLength = -1; +tSfx
try{ dPO|x+N,
URL url = new URL(siteInfoBean.getSSiteURL()); `ot<BwxJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Md(h-wYr
httpConnection.setRequestProperty("User-Agent","NetFox"); (cLcY%$
kjOPsz*0
fjwUh>[ }
int responseCode=httpConnection.getResponseCode(); ts=KAdcJ
if(responseCode>=400) A57e]2_
{ "5@k\?x"
processErrorCode(responseCode); ._5"FUg
return -2; //-2 represent access is error ed6eC8@
} &R~)/y0]
IolKe:'>@
:HTV8;yc
String sHeader; f{j(H?5
Wi3St`$
ZXL
for(int i=1;;i++) ,s.{R
{ <oP"kh<D4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "2a&G3}t"
//Utility.log(in.readLine()); AKkr )VgY
sHeader=httpConnection.getHeaderFieldKey(i); e~iPN.'1
if(sHeader!=null) =%IBl]Z!"
{ >;M?f!
if(sHeader.equals("Content-Length")) 9Vh>ty1|_
{ VGtKW kVH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jUg.Y98
break; EXD Qr'"
} i!+Wv-
} D^jyG6Ch
else Sx|)GTJJ|-
break; )Fw{|7@N
} i!k5P".o^
} O2 sAt3'
catch(IOException e){e.printStackTrace ();} b2p;-rv
catch(Exception e){e.printStackTrace ();} >t Ll|O+
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g (:%E
Utility.log(nFileLength); c[RkiV3
_(.,<R5
oM4Q_An
return nFileLength; >L{s[pLJ
} o6LZ05Z-&
8R;A5o,
E`aAPk_y
//保存下载信息（文件指针位置） M);@XcS
private void write_nPos() U6M3,"?
{ k~+(X|!5w
try{ }'.k
output = new DataOutputStream(new FileOutputStream(tmpFile)); <~}#Q,9
output.writeInt(nStartPos.length); nm.~~h+8M
for(int i=0;i<nStartPos.length;i++) r"uOf;m
{ X5`#da
// output.writeLong(nPos); 9u&q{I
output.writeLong(fileSplitterFetch.nStartPos); <!qv$3/7
output.writeLong(fileSplitterFetch.nEndPos); 4_'($FC1
} 2&Hn%q)
output.close(); u{SJ#3C5
} !W3bHy:C"
catch(IOException e){e.printStackTrace ();} ]BiLLDz(
catch(Exception e){e.printStackTrace ();} map#4\
} gk.c"$2
\Rff3$
0>KW94
//读取保存的下载信息（文件指针位置） p[Yja y+
private void read_nPos() WP b4L9<
{ K9 tuiD+j
try{ %/r}_V(UN
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (ev(~Wc
int nCount = input.readInt(); /18VQ
nStartPos = new long[nCount]; PpF"n[j
nEndPos = new long[nCount]; O?I~XM'S
for(int i=0;i<nStartPos.length;i++) ">V.nao
{ yu>DVD
nStartPos = input.readLong(); ~ d!F|BH4
nEndPos = input.readLong(); (&y~\t]H
} ]IZn#gnM
input.close(); ',<Bo{
} zLB7'7oP
catch(IOException e){e.printStackTrace ();} X\dPQwasM
catch(Exception e){e.printStackTrace ();} ~c*$w O\
} 8ezdU"
G6?+Qzr
28N v'
private void processErrorCode(int nErrorCode) a?]"|tQ'
{ ;E{k+vkqy
System.err.println("Error Code : " + nErrorCode); yS)73s/MrY
} V7\@g
B]xZ 4Y
'@epiF&
//停止文件下载 J4Tc q
public void siteStop() RIDzNdM>U
{ }hPFd
bStop = true; <E`Ygac
for(int i=0;i<nStartPos.length;i++) ,( ?q
fileSplitterFetch.splitterStop(); I2R" Y<
ckWK+
>hcze<^S
} A_mVe\(*M
} $aFCe}3b<
//负责部分文件的抓取 ",hPy[k
**FileSplitterFetch.java \k69 S/O
*/ +UGWTO\#ha
package NetFox; xpb,Nzwt^
NLz[F`I
^lp#j;Df
import java.io.*; q4~w D
import java.net.*; j m]d:=4_
y]veqa
3wQUNv0z
public class FileSplitterFetch extends Thread { 2{sx"/k\A
^=lh|C\#
rv\yS:2
String sURL; //File URL P!apAr
long nStartPos; //File Snippet Start Position wePhH*nQ>
long nEndPos; //File Snippet End Position g2&%bNQ-5
int nThreadID; //Thread's ID (pl|RmmDz
boolean bDownOver = false; //Downing is over ^"?fZSC
boolean bStop = false; //Stop identical =y$|2(6
FileAccessI fileAccessI = null; //File Access interface :'pLuN
#9a\Ab
7t@r}rC,K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v|&Nh?r
{ hPP,D\#
this.sURL = sURL; []vt\I ;
this.nStartPos = nStart; 4w\@D>@}H
this.nEndPos = nEnd; /ehmy(zL
nThreadID = id; ^J TrytIB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [K\Vc9
} ~'[0-_]=f
m4<5jC`-M
[f?fA[,[
public void run() X(`wj~45VX
{ r^m8kYezQ
while(nStartPos < nEndPos && !bStop) `k 5'nnyP
{ J ^y1=PM
IYo{eX~=
~q.a<B`,t
try{ 9uNkd2#
URL url = new URL(sURL); kma)DW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /5l"rni
httpConnection.setRequestProperty("User-Agent","NetFox"); GbLuXU
String sProperty = "bytes="+nStartPos+"-"; 1TagQ
httpConnection.setRequestProperty("RANGE",sProperty); <yw6Om:n<
Utility.log(sProperty); xE2sb*
&RzkM4"
WB7pdSZ
InputStream input = httpConnection.getInputStream(); xnfMx$fD
//logResponseHead(httpConnection); u?J!3ZEtb
nkp,
5 +Ei!E89
byte[] b = new byte[1024]; us,!U
int nRead; *u i!|;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v*.[O/,EBR
{ JjXuy7XQ
nStartPos += fileAccessI.write(b,0,nRead); 3u)NkS=
//if(nThreadID == 1) e#+u8LrN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '\MYC8"
} sUCI+)cM3
>;$C@
)tq&l>0h
Utility.log("Thread " + nThreadID + " is over!"); _XO3ml\x@
bDownOver = true; Mj guH5Uy
//nPos = fileAccessI.write (b,0,nRead); JBYmy_Su
} %z0;77[1I
catch(Exception e){e.printStackTrace ();} 2~*J<iO&l
} C V{kP8#
} . paA0j
1kd\Fq^z$
]WsQ=
//打印回应的头信息 ]~Su
public void logResponseHead(HttpURLConnection con) uX!5G:x]
{ 5Hli@:B2s
for(int i=1;;i++) y&-1SP<
{ IpJMq^Z
String header=con.getHeaderFieldKey(i); klwC.=?(j"
if(header!=null) PQkFzyk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1[; 7Ay
Utility.log(header+" : "+con.getHeaderField(header)); [{i"Au]
else )2tDX=D
break; u\jQe@j '
} iOFp9i=j
} AqdQiZ^9
K-a~Kr
<Z nVWER
public void splitterStop() P?#I9y7iP
{ _|'e Az
bStop = true; hyHeyDO2
} z!M8lpIM
4 Wb^$i!
hLv~N}
} lBpy0lo#
F&Bh\C)]
r+0<A.''a
/* Z}8khNCYr
**FileAccess.java 0Z m^6T
*//文件访问(定位，写) t-gLh(-.
package NetFox; KWq&<X5
import java.io.*; l"{1v~I
-E$(<Pow~\
sU|\? pJ
public class FileAccessI implements Serializable{ k%|Sl>{Ir
?ufX3yia
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KF%tF4^+|
RandomAccessFile oSavedFile; l\HLlwYO
long nPos; JNJ96wnX1
;v*J:Mn/=
|[ )e5Xhd
public FileAccessI() throws IOException ]52.nxs~
{ uZg[PS=@!X
this("",0); Fv<^\q
} Un~8N
$ #*";b)QY
C8xxR~mq
public FileAccessI(String sName,long nPos) throws IOException Cwh*AKq(
{ or8`.hEHI
oSavedFile = new RandomAccessFile(sName,"rw"); *%nV<}e^_=
this.nPos = nPos; xpO'.xEs
oSavedFile.seek(nPos); TEzMFu+V
} PXx:JZsju
&(Yv&jX
SyB2A\A
public synchronized int write(byte[] b,int nStart,int nLen) [J{M'+a
{ zAZ+'9LB
int n = -1; '1 }ybSG
try{ s-Z<
oSavedFile.write(b,nStart,nLen); mnG\qsKNLK
n = nLen; BQ;F`!Hx?
} '#oNOU
catch(IOException e) Rs +),
{ F%]ZyO9
e.printStackTrace (); <TDp8t9bU
} -5 Q gJ
B&M-em=
,\Q^[e!m~
return n; oOAn 5t@
} C3]"y7
YAc~,N
R^ln-H;
} DH>>u
t|5T,YFG
WXj iKW(
/* \{@n>Mh
**SiteInfoBean.java $!ATj`}kb
*/ V?zCON
package NetFox; T[L7-5U0
C5F=J8pY
)&") J}@
public class SiteInfoBean { -Gyj]v5y`c
Cd7imj
YjR`}rdwo
private String sSiteURL; //Site's URL {tDH !sX
private String sFilePath; //Saved File's Path \Qgc7ev
private String sFileName; //Saved File's Name ;k=&ZV
private int nSplitter; //Count of Splited Downloading File c{,VU.5/
Jqp;8DV}
nn?h;KzB
public SiteInfoBean() y!kU0
{//nSplitter的缺省值为5 %`# HGji)
//default value of nSplitter is 5 ]Uu:t
this("","","",5); 9sI&&Jg
} b)(rlX
d$gT,+|vu
#GbfFoE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }|j\QjH
{ "8#EA<lsS
sSiteURL= sURL; JnY.]:
sFilePath = sPath; KB$SB25m
sFileName = sName; 6]^~yby P
this.nSplitter = nSpiltter; Pe,:FIp,
0|=,!sY
`mE>h4
} K-2oSS56
us7t>EMmB
IyPk3N
public String getSSiteURL() itn<c2UyA
{ ng6".u9
return sSiteURL; ]=28s *@
} iU/v;T(
f =MP1q[
O,[9E
public void setSSiteURL(String value) _)%Sz"g^Ix
{ .ED8b5t|
sSiteURL = value; A?+0Ce&qL
} hR+\,P#G[
wV\.NQtS
U^&,xz$Cg
public String getSFilePath() k5@PZFV
{ h0oe'Xov
return sFilePath; |\<L7|hb9
} Errs6
crbph.0
/=K(5Xd
public void setSFilePath(String value) G&z^AV
{ /_D_W,#P
sFilePath = value; 3Ow bU
} t8ZzBD!dP
f6])M)
{bP )Fon
public String getSFileName() [lz#+~rOS
{ \n<9R8g5
return sFileName; mFgrT
} /iw$\F |8
35KRJY#
:lBw0{fP
public void setSFileName(String value) )C>8B`^S
{ #;])/8R%
sFileName = value; >n"4M~I
} [e f&|Pi-
^iqy|zNtn
s`2q(`}
public int getNSplitter() \#sdN#e;XA
{ bamQ]>0|>!
return nSplitter; _zK ~9/5
} P\ia ?9
]RxJ^'a63
?ocBRla
public void setNSplitter(int nCount) r]=Z :
{ =oT4!OUf
nSplitter = nCount; &hcD/*_Z
} ;Qi0j<dXd
} zhgvqg-
\OW.?1d
{WvYb,
/* {`ByZB
**Utility.java hlBMRx49
*/ ,}:}"cl
package NetFox; *_sSM+S
dlRTxb^Y>u
.x'?&7#(
public class Utility { -A^o5s
!Bv.@~
+yI2G! $T9
public Utility() @+7CfvM
{ ~5>k_\G8
D4O^5?F)|
)8`i%2i=
} -)Hc^'.
{_R{gpj'
//线程睡眠 V<ii
public static void sleep(int nSecond) ^6QzaC3
{ `b KJ
try{ ENy$sS6[D
Thread.sleep(nSecond); jx#9
} yioX^`Fc(~
catch(Exception e) ~5o2jTNy`p
{ F<4>g+Ag
e.printStackTrace (); D]twid~OS
} K]&i9`>N
} }Ud'j'QMy
u&Yd+');
//日志 "$.B@[iY@
public static void log(String sMsg) [0!*<%BgK'
{ kjF4c6v
System.err.println(sMsg); }t*:EgfI
} 3Mq%3jX
'iU+mRLp
-_M':
public static void log(int sMsg) 73l,PJ
{ A_Y5{6@
System.err.println(sMsg); Oe21noL
} `Y3\R#
} O4cBn{Dq9
&ZL4/e
G2&,R{L6w
/* hd W7Qck"
**TestMethod.java %6la@i
*/ tB`IBuy9!"
package NetFox; i_:#][nWX
{^?:-#~h
2^qJ'<2]M
public class TestMethod { gnadx52FP
X!6$<8+1OV
m^ /s}WEqp
public TestMethod() JfRLqA/
{ ///xx/weblogic60b2_win.exe ?DE{4Ti/[
try{ akG|ic-~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n}C0gt-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i (`Q{l
SiteFileFetch fileFetch = new SiteFileFetch(bean); IEe;ygL#
fileFetch.start(); 'vV+Wu#[
} JkQ\r$Y.
catch(Exception e){e.printStackTrace ();} x *a_43`
y+ 4#Iy
K j~!E H"
} }l&y8,[:
6,!$S2(zT
]GDjR'[z
public static void main(String[] args) s@p:XO
{ {I/t3.R`
new TestMethod(); "jf_xZ$H-
} [Wxf,rW i
} U#%+FLX@w
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