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)); B.mbKntK)R
} ]6BmCh
for(int i=0;i<nEndPos.length-1;i++) *Qg5Z
{ ZE8/ m")
nEndPos = nStartPos[i+1]; f;Bfh3
} .eabtGO,
nEndPos[nEndPos.length-1] = nFileLength; R=amKLD?
} Z0ncN])
} ,M@m4bx
_:gGD8
S $_Y/x
//启动子线程 <duBwkiG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /iTUex7T
for(int i=0;i<nStartPos.length;i++) >1r[]&8
{ B221}t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |)?aH2IL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hX8gV~E=y
nStartPos,nEndPos,i); 1t[;`iZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fATA%eA8;
fileSplitterFetch.start(); C^,4`OI
} &V#zkW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {yHB2=nI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gR;8ht(pd(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uspkn1-
nEndPos = " + nFileLength); ;c X^8;F0
// fileSplitterFetch[nPos.length-1].start(); Sj0 ucnuHi
<E[HlL
^%5~;
//等待子线程结束 ;5D@kS^
//int count = 0; i.&Kpw9;m
//是否结束while循环 U1>
boolean breakWhile = false; O2q=gYX>\
9iGE`1N%E
Ld\LKwo
while(!bStop) 5 dfe@$
{ N[,VSO&
write_nPos(); {1Ju}=69
Utility.sleep(500); 1 ;\]D9i
breakWhile = true; bB;~,W&E1
Q7uAf3
*>aZc::
for(int i=0;i<nStartPos.length;i++) +~w?Xw,
{ <V$Y6(uMs
if(!fileSplitterFetch.bDownOver) O&#S4]Y
{ `;5VH]V
breakWhile = false; rL%]S&M9
break; >@)*Sn9"
} {d1N&
} QiTR-M2C!
if(breakWhile) FJa[ToZ4+
break; U]V3DDN
I|KY+k> /
8h&oSOkQk,
//count++; `Di ^6UK(
//if(count>4) fiE>H~
// siteStop(); nDHHYp
} c~gNH%1XN
5JBB+g
vzY'+9q1.
System.err.println("文件下载结束！"); ]aC':55(
} ,DQGv_
catch(Exception e){e.printStackTrace ();} L$Hx?^3
} z(g%ue\
a=J@yK
iK5]y+@8
//获得文件长度 UF&0&`@
public long getFileSize() Vs_\ykO
{ r6d0x
int nFileLength = -1; MzEm*`<
try{ HGO#e
URL url = new URL(siteInfoBean.getSSiteURL()); !,cQ'*<W8-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /d0Q>v.g
httpConnection.setRequestProperty("User-Agent","NetFox"); f >mhFy
,f8}q]FTA
4Qa@`
int responseCode=httpConnection.getResponseCode(); )XLj[6j0
if(responseCode>=400) >Z#uFt0<Pm
{ N]1V1c$G*
processErrorCode(responseCode); 1YOg1 n+k
return -2; //-2 represent access is error Gw ~{V
} Qg'c?[~W@
dtB[m^$
==%`e/~Y
String sHeader; On#;)35M
b#D9eJhS
z.eJEK
for(int i=1;;i++) 3R5K}ZBi%
{ *j|/2+pq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F(Lb8\to\M
//Utility.log(in.readLine()); 5;IT64&]
sHeader=httpConnection.getHeaderFieldKey(i); BZovtm3E
if(sHeader!=null) k$ZRZ{ E+
{ )Rjb/3*!
if(sHeader.equals("Content-Length")) 99<4t$KH
{ E%<w5d.lq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v<L=!-b^
break; nd.57@*M
} ^I]LoG:
} P@qMJ}<j
else 7~_{.f
break; v1LKU
} `wNm%*g
} OENzG~
catch(IOException e){e.printStackTrace ();} Y\.-v\uJu
catch(Exception e){e.printStackTrace ();} Q;4}gUmI$
FoE|Js
xDR9_
Utility.log(nFileLength); :]vA2
iV5}U2Vh
Rw{$L~\
return nFileLength; IikG/8lP
} "hL9f=w
{DU"]c/S
^#]c0
//保存下载信息（文件指针位置） ?nQ_w0j
private void write_nPos() _b>F#nD,'%
{ *i@sUM?K
try{ ,Z^Ca15z
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2zz,(RA
output.writeInt(nStartPos.length); ? m&IF<b
for(int i=0;i<nStartPos.length;i++) :.Y|I[\E%
{ dVa!.q_3
// output.writeLong(nPos); O/mR9[}
output.writeLong(fileSplitterFetch.nStartPos); r]v&t
output.writeLong(fileSplitterFetch.nEndPos); &=YSM.G
} yH*hL0mO
output.close(); :*^:T_U
} Vzpt(_><
catch(IOException e){e.printStackTrace ();} 59.$ULQVMY
catch(Exception e){e.printStackTrace ();} X4a^mw\"
} q(,cYu
!{;[xXK4M
! 0^;;'
//读取保存的下载信息（文件指针位置） k^z0Lo|)'
private void read_nPos() =4eUAeH {w
{ #,G1R7
try{ 1Q]Rd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |+98h&U~
int nCount = input.readInt(); Z.quh;
nStartPos = new long[nCount]; _1ew(x2J
nEndPos = new long[nCount]; 5UE409Gn'
for(int i=0;i<nStartPos.length;i++) <$%ql'=
{ 9z:K1
nStartPos = input.readLong(); T.kyV|
nEndPos = input.readLong(); kBo;h.[l
} -LTKpN`[@
input.close(); +=7:4LFOL
} `ruNA>M
catch(IOException e){e.printStackTrace ();} _3/ec]1
catch(Exception e){e.printStackTrace ();} Jm4#V~w
} 5k]XQxc6_
[u`6^TycP
f-4.WW2FN
private void processErrorCode(int nErrorCode) JBz}|MD
{ 9RH"d[%yc}
System.err.println("Error Code : " + nErrorCode); %<ic%gt`#
} v9=}S\=Cd
s.VA!@F5
$/+so;KD
//停止文件下载 %#u.J
public void siteStop() l;OYUq~F
{ [>f]@>
bStop = true; /prYSRn8
for(int i=0;i<nStartPos.length;i++) Z0$] tS
fileSplitterFetch.splitterStop(); Z0-ytODII
Vo\H<_=G
>)NQH9'1
} ~O{W;Cyh
} \6o\+OQk
//负责部分文件的抓取 3+ =I;nj
**FileSplitterFetch.java YGp)Oy}:
*/ /;Yy@oc
package NetFox; `N}d}O8
b0rX QMu
\:Za[6
import java.io.*; =LI:S|[4
import java.net.*; |f\D>Y%)
_1aGtX|W
<J&7]6Z
public class FileSplitterFetch extends Thread { =\Iu$2r`
z<B CLP
='}#`',
String sURL; //File URL hd2'AlB
long nStartPos; //File Snippet Start Position yzR=A%V8A
long nEndPos; //File Snippet End Position %D`o
int nThreadID; //Thread's ID yS!(Ap
boolean bDownOver = false; //Downing is over 8O7Yv<
boolean bStop = false; //Stop identical @E%DP9.I
FileAccessI fileAccessI = null; //File Access interface L[y Pjw:0
-R0/o7
zT[6eZ8m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &J$##B
{ (u&`Ij9
this.sURL = sURL; e4\dpvL
this.nStartPos = nStart; W\8Ln>
this.nEndPos = nEnd; Z(e^iH
nThreadID = id; ?qmp_2:WU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jnJZ#=)
} :U'Cor H
e)@3m.
X:EEPGE
public void run() 7C7>y/uS
{ Q9c)k{QZ
while(nStartPos < nEndPos && !bStop) #H~_K}Ks
{ O,s.D,S
P|xG\3@Z
F PR`tE
try{ D."=k{r.
URL url = new URL(sURL); %d2!\x%bG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BI/&dKM
httpConnection.setRequestProperty("User-Agent","NetFox"); W2]TRO
String sProperty = "bytes="+nStartPos+"-"; @0NJ{
httpConnection.setRequestProperty("RANGE",sProperty); 0fArF*
Utility.log(sProperty); oehaQ#e
1/;o
Y3Oz'%B
InputStream input = httpConnection.getInputStream(); D#Kuo$
//logResponseHead(httpConnection); fThgK;Qy'U
n?xTkkr0
tU@zhGb
byte[] b = new byte[1024]; "35A/V
int nRead; -tLO.JK<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c5% 6Y2W0
{ e,gyQjJR
nStartPos += fileAccessI.write(b,0,nRead); pHC/(6?
//if(nThreadID == 1) .c+9P<VmC}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @?kJ).
} #_JYh?
Q@S-f:!
$IX\O
Utility.log("Thread " + nThreadID + " is over!"); O )d[8jw"
bDownOver = true; * F4UAQzYb
//nPos = fileAccessI.write (b,0,nRead); nP3 E
} UvJ;A
catch(Exception e){e.printStackTrace ();} h6v077qG
} b5a.go
} q7\Ovjs0
-c*\o3)
nZk+
//打印回应的头信息 *O~e T
public void logResponseHead(HttpURLConnection con) %*}Y6tl'|
{ "ju'UOcS/
for(int i=1;;i++) iE].&>w
{ F@YKFk+a
String header=con.getHeaderFieldKey(i); BuOgOYh9
if(header!=null) Fhf<T`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EGVM)ur
Utility.log(header+" : "+con.getHeaderField(header)); mtAE
else ?C-Towo=i
break; Ib=x~za@n
} qv*7K@
} @N@F,~[RR2
3gEMRy*+
HD>q(cK_|8
public void splitterStop() bulS&dAX
{ YJeyIYCs<
bStop = true; #5} wuj%5
} O`[aU%4b
W?woNt'n
4rg2y]
} soRv1)el
yx38g ca
zeb=8Dg :
/* tq1CwzRX
**FileAccess.java 4T6 {Y
*//文件访问(定位，写) IxZb$h[
package NetFox; V)ig)(CT
import java.io.*; Yf@e=:
L{-LX=G^
KLWn?`
public class FileAccessI implements Serializable{ .B2]xfo"`
3?I;ovsM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Pe73g%
RandomAccessFile oSavedFile; , t5 '
long nPos; $;N*cH~
4<dcB@v
*cuuzi&
public FileAccessI() throws IOException E H:T
{ FzQTDu9
this("",0); 'k0[rDFc#3
} D\dWt1n
l7H qo)
YyAJ m^o
public FileAccessI(String sName,long nPos) throws IOException dO> VwP
{ '7^M{y/dU
oSavedFile = new RandomAccessFile(sName,"rw"); RD7^&
this.nPos = nPos; sUJ%x#u}Fk
oSavedFile.seek(nPos); )SF}2?7e
} `{k"8#4:qA
1RcSTg
U1_@F$mq<
public synchronized int write(byte[] b,int nStart,int nLen) P262Q&.}d
{ }o4N<%/+
int n = -1; v{zMO:3
try{ }/tf>?c
oSavedFile.write(b,nStart,nLen); #'D" 'B
n = nLen; eV:9y
} C?v[Z]t
catch(IOException e) xw^R@H
{ zi R5:d3
e.printStackTrace (); #6Fez`A
} 'm1N/)F
B~]5$-
Qd}m`YW-f$
return n; VVH.2&`I
} d@`M CchCB
]^':Bmq
|F,R&<2
} dI&!e#Y
j`^$#
$vC1 K5sLk
/* QO;N9ZI
**SiteInfoBean.java zJP6F.Ov!
*/ @k[R/,#'[t
package NetFox; F<>!kK/c
B~o\+n
3bk|<7tl
public class SiteInfoBean { )[0T16
f` =CpO*
_XJ2fA )
private String sSiteURL; //Site's URL (" LQll9
private String sFilePath; //Saved File's Path +a-6Q ~
private String sFileName; //Saved File's Name +fvaUV_-
private int nSplitter; //Count of Splited Downloading File d ;vT ~;
6"Bic rY
* #jsgj[
public SiteInfoBean() | N0Z-|
{//nSplitter的缺省值为5 q0f3="
//default value of nSplitter is 5 ^O^l(e!3
this("","","",5); lY|Jr{+Ln
} U2uF&6v
}*.0N;;C
*K> l*l(f]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =]:>"_jN
{ GKN%Tv:D_
sSiteURL= sURL; !vG'J\*xc
sFilePath = sPath; WVVJ
sFileName = sName; f|O{#AC
this.nSplitter = nSpiltter; n6s}ww)
(Qa/EkE^*w
Cmc3k,t
} aLIBD'z
0a-:<zm
/rUo{j
public String getSSiteURL() W6On93sa
{ 9Xx's%U
return sSiteURL; m(pE5B(
} EwOV;>@T?
V(Ub!n:j
K|dso]b/
public void setSSiteURL(String value) .e_cgad :
{ ^]{R.(#z
sSiteURL = value; ByCnD
} `jwa<N4e@
7o8{mp'_
V<Z[ nq
public String getSFilePath() s kg*
{ ]XI*Wsn
return sFilePath; /_`lz^
} gx%|Pgd
ABUSTf<
@}u9Rn*d;
public void setSFilePath(String value) ],P;WPU
{ v{}#?=I5
sFilePath = value; ,"B+r6}EF
} 9K9DF1SOa
=i~}84>
-jMJAYjV
public String getSFileName() G "73=8d
{ ~%YBI9$+
return sFileName; *zr(Zv
} 6`f2-f9%iq
,yd?gP-O
E9~Ghx.
public void setSFileName(String value) K_dOq68_
{ kT;S4B
sFileName = value; -wjN"g<
} F&&$Qn_+
br|;'i%(
dPhQ :sd>
public int getNSplitter() ]\!?qsT3}
{ jYe'V#5S#
return nSplitter; U"Zmv
} )I3NeKWz
?Wz8[u
eopD5
public void setNSplitter(int nCount) L'F<ev
{ {?yr'*
nSplitter = nCount; 6L)%T02C
} s0PrbL%_`
} ^Vpq$'!
gvLf|+m
nw-I|PVTNa
/* ]C) 4
**Utility.java J>\B`E
*/ 92EWIHEWZ
package NetFox; Z?\2F%
}mAa}{_
rb|U;)C
public class Utility { B'fb^n<
5O\*h;U 6
3g >B"t
public Utility() a[ex[TRKe
{ ,G2TVjz
2sJ(awN>
92 [;Y
} 3\B>lKhQ
vvm0t"|\
//线程睡眠 +(h\fm7*-
public static void sleep(int nSecond) zzyHoZJP
{ rnF/H=I/
try{ p>upA)W]
Thread.sleep(nSecond); d!$Z(W0
} 7k rUKYVo
catch(Exception e) _]Zs,Hy
{ q#s,-uu
e.printStackTrace (); !TUrQ
} ,gS;m &!'J
} m&?#;J|B$
9M:O0)s
//日志 cZ|\.0-
public static void log(String sMsg) v#!%GEg1r
{ v61[.oS
System.err.println(sMsg); ia MUsa{
} <"_d]?,
IyPwP*A
:AE&Ny4
public static void log(int sMsg) <>8WQn,K
{ mVy|{Oh
System.err.println(sMsg); ]bK=FIK2
} 9pX&ZjYP-
} T87m?a$
gntxNp[9T
3de_V|%
/* >M`CVUf
**TestMethod.java bdc&1I$
*/ s#WAR]x0x
package NetFox; bLwAXW2K+
iB498t
3J5!oF{H
public class TestMethod { 'JRvP!]
`tn{ei
D8xmE2%
public TestMethod() 1A\OC
{ ///xx/weblogic60b2_win.exe H(Z88.OM
try{ MerFZd 1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4B^ZnFJ%m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u4/kR
SiteFileFetch fileFetch = new SiteFileFetch(bean); {o>j6RS\
fileFetch.start(); nYX@J6!
} !Y[lQXv
catch(Exception e){e.printStackTrace ();} zlEX+=3
P3=W|81e
,=#F//
} BYMi6wts
o<|P9#(U"
}3OKC2K~
public static void main(String[] args) K[!&b0O
{ [_Qa9e
new TestMethod(); @]ytla>d
} =_:et0
} d%o&+l#
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