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)); tfv]AC7x
} B4|%E$1+
for(int i=0;i<nEndPos.length-1;i++) & bw1
{ 053W2Si
nEndPos = nStartPos[i+1]; s.GhquFCrU
} '{oe}].,
nEndPos[nEndPos.length-1] = nFileLength; 4qm5`o\hb
} eEc;w#
} p Y>yJ)
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(J^ Tss
//启动子线程 o!\O)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A<.Q&4jb
for(int i=0;i<nStartPos.length;i++) #sqDZ]\B
{ /{kyjf[o&*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *=|i"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^~`8 - TE
nStartPos,nEndPos,i); P^h2w%6'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y6D=tb
fileSplitterFetch.start(); ryn)
} [Z5x_.k"I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZA9']u%EJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W>DpDrO4ml
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +j@|D@z
nEndPos = " + nFileLength); U.^)|IHW
// fileSplitterFetch[nPos.length-1].start(); h;ShNU
"!Qhk3*
ReK@~#hLY
//等待子线程结束 )7i?8XiSZF
//int count = 0; 'Ux_X:,:;
//是否结束while循环 |y:DLsom?i
boolean breakWhile = false; 3mm`8!R
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+qz)KtJS
while(!bStop) 9lD,aOb
{ ~hxB Pn."
write_nPos(); q]r!5&Z
Utility.sleep(500); "BVz5?
breakWhile = true; quKD\hL$
uRL3v01?H0
AV2q*
for(int i=0;i<nStartPos.length;i++) _ma4
{ Y?5yzD:
if(!fileSplitterFetch.bDownOver) VUnEI oKM
{ ,F-tvSc\Q
breakWhile = false; ?xf;#J+{8
break; wl{p,[]
} [{{?e6J
} 3,F/i+@
if(breakWhile) h?ia4t
break; +I Ze`M%n
<7jb4n<
G1nW{vce
//count++; i Lm1l
//if(count>4) ]Z84w!z
// siteStop(); }DM2#E`_
} =:g^_Hy
hx2C<;s4
.gPsJ?b
System.err.println("文件下载结束！"); :>;psR
} 4vX]c
catch(Exception e){e.printStackTrace ();} 9Y4N
} kK1qFe?]
{&<}*4D
qIqk@u
//获得文件长度 Y(:OfC?
public long getFileSize() Z~,.l
{ )R +o8C
int nFileLength = -1; sTA/2d
try{ #y*=UV|h
URL url = new URL(siteInfoBean.getSSiteURL()); K?;p:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); - dOT/%Ux
httpConnection.setRequestProperty("User-Agent","NetFox"); L$Leo6<3a
]8_h9ziz
z\E"={P&
int responseCode=httpConnection.getResponseCode(); \=@r1[d
if(responseCode>=400) RYV6hp)|
{ Gzir>'d2'V
processErrorCode(responseCode); bMUIe\/v[
return -2; //-2 represent access is error rgYuF,BT.
} $HXB !$d
28)TXRr-
b"Mq7&cf
String sHeader; k41la?
*M|\B|A.
~4>Xi* B
for(int i=1;;i++) &53#`WgJ
{ <{U{pCT%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Fm;)7.% >
//Utility.log(in.readLine()); ?V{k\1A
sHeader=httpConnection.getHeaderFieldKey(i); kdUGmR0d
if(sHeader!=null) hKTg~y^
{ )]%9Tgn
if(sHeader.equals("Content-Length")) `JE>GZY
{ 4'd{H Rs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #LN I&5
break; 5i/E=D
} -PnC^r0L$
} NqZRS>60v
else $&C(oh$:
break; q%k+x)
} )a^Yor)o"
} uTU4Fn\$L
catch(IOException e){e.printStackTrace ();} 6oP{P_Pxi
catch(Exception e){e.printStackTrace ();} h3kHI?jMWG
tRy D@}
FR}H$R7#
Utility.log(nFileLength); `Q&]dE=
&1p8#i
+r0eTP=zf
return nFileLength; 4{DeF@@
} bS<@Rd{g
Jrk^J6aa
qp W#!Vbx
//保存下载信息（文件指针位置） 2ZO'X9
private void write_nPos() [)3 U])w/
{ B (1,Rq[
try{ _onp%*
output = new DataOutputStream(new FileOutputStream(tmpFile)); p0rwiBC=q
output.writeInt(nStartPos.length); eCp|QSXE
for(int i=0;i<nStartPos.length;i++) >$mSFJz5S
{ ^)q2\YE;
// output.writeLong(nPos); (J*w./
output.writeLong(fileSplitterFetch.nStartPos); UPKi/)C;
output.writeLong(fileSplitterFetch.nEndPos); 7rSUSra
} ^@Qi&g`lr?
output.close(); lk +K+Ra/
} ^2r}_AX
catch(IOException e){e.printStackTrace ();} ;1.>"zX(
catch(Exception e){e.printStackTrace ();} +?iM$}8!U
} <s-@!8*(
?*'$(}r3
,8IAhQa
//读取保存的下载信息（文件指针位置） w`}9/s;$
private void read_nPos() s1vrzze
{ w"v'dU^
try{ ~9?U_ahfVt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gOyY#]g
int nCount = input.readInt(); ^Q=y^fx1
nStartPos = new long[nCount]; :Nz?<3R0\
nEndPos = new long[nCount]; vSYKe
for(int i=0;i<nStartPos.length;i++) !/}FPM_
{ %?f:"
nStartPos = input.readLong(); =$8@JF'
nEndPos = input.readLong(); [S]!+YBK
} d=Do@) m|
input.close(); {TncqA
} c,q"}nE8w
catch(IOException e){e.printStackTrace ();} z"K( bw6
catch(Exception e){e.printStackTrace ();} q{GSsDo-:V
} p%"yBpSK
b;L>%;
}E5#X R
private void processErrorCode(int nErrorCode) ay(!H~q_U
{ )@qup _M@
System.err.println("Error Code : " + nErrorCode); (a}
} P=^#%7J/l
W3/ 7BW`
5)yOw|Bd
//停止文件下载 ChTXvkdH
public void siteStop() ,iVPcza
{ ]&:b<]K3
bStop = true; kV ,G,wo
for(int i=0;i<nStartPos.length;i++) h1XMx'}B
fileSplitterFetch.splitterStop(); |:9Ir^
5}eQaW48
cVay=5].
} -@L's{J{M
} ?Hi}nsw
//负责部分文件的抓取 sc8DY!|OYN
**FileSplitterFetch.java Mjj}E >&
*/ `x} Dk<HF
package NetFox; "XNu-_$N<a
=#(0)p$EC
i~)NQmH<
import java.io.*; Px?Ao0)Z,
import java.net.*; A)zPaXZ
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&|N%#pYS
public class FileSplitterFetch extends Thread { fYhR#FVI
D#7_TKX
,?k%jcR
String sURL; //File URL 5#0e={X
long nStartPos; //File Snippet Start Position ]G0dS Fh{j
long nEndPos; //File Snippet End Position '_qQrP#
int nThreadID; //Thread's ID %5h^`lp
boolean bDownOver = false; //Downing is over #+"4&:my
boolean bStop = false; //Stop identical 85D^@{
FileAccessI fileAccessI = null; //File Access interface pDq#8*q+v
#9`rXEz
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w(/DTQc~d
{ 1n'$Ji7
this.sURL = sURL; #SQvXMT
this.nStartPos = nStart; &Vt2be*
this.nEndPos = nEnd; &xiOTkqB
nThreadID = id; s=N#CE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #, Q}NO#vT
} /2e%s:")h
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2QGMe}
public void run() b,sGq
{ wmo{YS3t|
while(nStartPos < nEndPos && !bStop) 2@ 9pr
{ W|dpFh`
fw' r.
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try{ r219M)D?
URL url = new URL(sURL); s>|Z7[*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0e+W/Tq
httpConnection.setRequestProperty("User-Agent","NetFox"); >5;N64]!)
String sProperty = "bytes="+nStartPos+"-"; ,?g=U8y|
httpConnection.setRequestProperty("RANGE",sProperty); sEce{"VC
Utility.log(sProperty); ^/>Wr'w
4\N_ G @
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InputStream input = httpConnection.getInputStream(); #JA}LA"l
//logResponseHead(httpConnection); 5"JU?e59M
2{ o0@
[ -ISR7D
byte[] b = new byte[1024]; LJGJ|P
int nRead; r C_d$Jv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hq<5lE^
{ ,+tPRkwA^
nStartPos += fileAccessI.write(b,0,nRead); 3J%V%}mD
//if(nThreadID == 1) u#`+[AC`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ljPq2v ]
} 1^C|k(t
_>Pk8~m
NZLXN
Utility.log("Thread " + nThreadID + " is over!"); Ly9Q}dL
bDownOver = true; 2sKG(^=Z
//nPos = fileAccessI.write (b,0,nRead); .^i<xY
} k(P3LJcYQ
catch(Exception e){e.printStackTrace ();} Q|Pbt(44
} ~TDzq -U)
} BhKO_wQ?:J
L=,OZ9aA
}YQ:6I
//打印回应的头信息 &=6%>
public void logResponseHead(HttpURLConnection con) mD7}t
{ *z0K%@M
for(int i=1;;i++) D(Qa>B"1
{ W57&\PXYn
String header=con.getHeaderFieldKey(i); kMy<G8 s
if(header!=null) 2H[ ; v+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0p-#f|ET
Utility.log(header+" : "+con.getHeaderField(header)); FV A UR
else IX9K.f
break; 0[/vQ+O]2
} -kl;!:'.3
} A 4j<\xL
3gpo %
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public void splitterStop() sAi&A9"*
{ `(!NYx
bStop = true; j 1(T )T
} *>k!hq;j
$A`xhh[
!.EcP=S
} W,3zL.qH"
o(qEkR:4kd
3 >|uF
/* 3jF|Ic
**FileAccess.java -#aZF2z
*//文件访问(定位，写) &]< 3~6n
package NetFox; O)uOUB
import java.io.*; 66Gx.tE
(SF1y/g@=
=EW3&+Lt
public class FileAccessI implements Serializable{ vX+.e1m
5`~mqqR5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?E<c[*F05
RandomAccessFile oSavedFile; V&i2L.{G)
long nPos; .+yW%~0
R)+t]}
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public FileAccessI() throws IOException /b#q*x-b
{ d&jjWlHgEN
this("",0); BwxnDeG)
} rjUBLY1(
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public FileAccessI(String sName,long nPos) throws IOException E-fr}R}
{ ',ZF5T5z@
oSavedFile = new RandomAccessFile(sName,"rw"); 2n|CD|V$ux
this.nPos = nPos; %/T7Z;d
oSavedFile.seek(nPos); oG_C?(7>
} :p>hW!~
:CaTP%GW
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public synchronized int write(byte[] b,int nStart,int nLen) )eYDQA>J
{ ewnfeg1
int n = -1; jl}$HEI5m}
try{ ]JjK#eh
oSavedFile.write(b,nStart,nLen); 8o|P&q(v*
n = nLen; ,Ff n)+
} gn ?YF`
catch(IOException e) k4{:9zL1#?
{ ~Ky4+\6o>
e.printStackTrace (); !][F
} _BS 9GB
7,'kpyCj
-(#-I$z
return n; mS%4gx~~_n
} lb~E0U`\E`
iW;i!,
5~+XZA#2
} NTmi 2c
WUEHB
\Q&,ISO\
/* nY_?Jq
**SiteInfoBean.java VWi2(@R^
*/ !tNd\}@
package NetFox; !aNh!
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+e P.s_t
public class SiteInfoBean { W7=V{}b+
2YOKM#N]
s_ bR]G
private String sSiteURL; //Site's URL dqc1q:k?$
private String sFilePath; //Saved File's Path qZk:mlYd
private String sFileName; //Saved File's Name =Z,5$6%)
private int nSplitter; //Count of Splited Downloading File M#,Q ^rH#
H&4~Uo.5
Rc[0aj:
public SiteInfoBean() zY=jXa)K~
{//nSplitter的缺省值为5 OH6^GPF6
//default value of nSplitter is 5 &@v<nO-
this("","","",5); t'1Y@e
} O#eZ<hNV
9V 0}d2d
N|:'XwL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H?`g!cX
{ k<j"~S1
sSiteURL= sURL; M\D]ml~
sFilePath = sPath; ;inzyFbL=
sFileName = sName; p_2pU)%
this.nSplitter = nSpiltter; DWiBG
L":bI&V?:
_P7tnXww
} 1S:|3W
CN&
*>q/WLR
public String getSSiteURL() sZhMa>
{ ^3]UZ@
return sSiteURL; @;Opx."
} 9YN?
e8P-k3a"5:
K#mOSY;}
public void setSSiteURL(String value) \7v)iG|#G&
{ QM<y`cZ8
sSiteURL = value; .Y*f2A.v
} aP-<4uGx
S* R,FKg
kH948<fk3
public String getSFilePath() 9X}I>
{ G"dS+,Q
return sFilePath; J CGC
} SOf{Hx0C6
GK*v{`
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public void setSFilePath(String value) Vb|#MNf)
{ rN/|(@
sFilePath = value; :aAEJ
} `#mK*Buem}
h9s >LY
FMw&(
public String getSFileName() '0RwO[A#1
{ \2C`<h$fN
return sFileName; _D, ;MB&7
} NjuiD].
R^#@lI~
tt_o$D~kg
public void setSFileName(String value) SA"p\}"
{ <|B1wa:|
sFileName = value; Q \hY7Xq'
} s)J(/
p0:kz l4$
OO) ~HV4\
public int getNSplitter() +IFw_3$
{ /=?x{(B>
return nSplitter; #Pk$L+C
} YDJ4c;37
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XXZaKgsq
public void setNSplitter(int nCount) U(>4s]O6
{ <Zb/
nSplitter = nCount; H}}$V7]^),
} *e>]~Z,
} 7[#yu2
_qwQ;!9
;,h/
/* Kv&g5&N,
**Utility.java CY:d`4
*/ ~uWOdm-"[
package NetFox; 13k !'P
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public class Utility { friWW^
1c4/}3*
k%c{ETdE
public Utility() dUrElXbXd
{ ||7x;2e
&)d$t'7p
VosZJv=
} f|7\DeY9U
<W8t|jt
//线程睡眠 4*n#yVb/
public static void sleep(int nSecond) +n0r0:z0
{ p{A}pnjf
try{ 796\jf$
Thread.sleep(nSecond); %]gTm7 =t
} $@-P5WcRs
catch(Exception e) N?Q+>
{ u7%D6W~m0
e.printStackTrace (); Fxs;Fp
} ;ea]$9
} z;f2*F
8`>h}Q$
//日志 olB)p$aH#
public static void log(String sMsg) &F:IIo7
{ "Mw[P [w*
System.err.println(sMsg); 7"F*u :
} Ks^6.)
Y_&g="`Q
!l?.5Pm])
public static void log(int sMsg) $4kH3+WJ
{ -&x2&WE'
System.err.println(sMsg); 1/1Xk,E
} 'VyM{:8
} Xazo9J
ok^d@zI
=uk0@hy9b
/* ='ZRfb&
**TestMethod.java )~4II.`%^
*/ Mv544>:
package NetFox; "I?Am&>'
GcIDG`RX
\6n!3FLl
public class TestMethod { ZX!r1*c 6
6oaazB^L
h!~3Dw>,N
public TestMethod() o+`6LKg;
{ ///xx/weblogic60b2_win.exe l&4,v
try{ <U5wB]]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uzmk6G v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]wT 7*( Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); S:4crI
fileFetch.start(); WG*t::NN
} >^q7c8]~g
catch(Exception e){e.printStackTrace ();} XZ&KR.C,
geQ{EwO8n
gTgMqvt
} F>tQn4
h5%<+D<
(Fq5IGs
public static void main(String[] args) @2pu^k^
{ C*U'~qRK
new TestMethod(); ;k"Bse!/
} 6:GTD$Uz.
} UDhG :
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