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)); M ~;]d
} |(<A)C
for(int i=0;i<nEndPos.length-1;i++) -zg 6^f_pW
{ /HH_Zi0?N|
nEndPos = nStartPos[i+1]; VS\| f'E
} ;il+C!6zpf
nEndPos[nEndPos.length-1] = nFileLength; A]laS7Q
} :}UjX|D
} 82)%`$yZw[
e'yw8U5E/
g@'2 :'\
//启动子线程 >*/:"!u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }Ug$d>\
for(int i=0;i<nStartPos.length;i++) +~>cAWZq_
{ :d6]rOpX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j.!5&^;u4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EfB.K}b^
nStartPos,nEndPos,i); !hFzIp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qZdA%
fileSplitterFetch.start(); IyEfisOK?
} :HM~!7e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .6!cHL3ln
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); bt*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d]USk&8
nEndPos = " + nFileLength); "S+AkLe(
// fileSplitterFetch[nPos.length-1].start(); i#NtiZ.t=
N\"Hf=Y(~
mBxMDnh
//等待子线程结束 % *ng *
//int count = 0; 'l<Oj&E
//是否结束while循环 :-_"[:t 5Z
boolean breakWhile = false; O7%8FY
[!C!R$AMa
|No9eZ8>.
while(!bStop) 4p7j"d5
{ :IX,mDO
write_nPos(); o5['5?i}/
Utility.sleep(500); ;eJ|)*
breakWhile = true; :%gM Xsb
$ y(Qdb
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for(int i=0;i<nStartPos.length;i++) OHwH(}H?
{ D9 Mst6
if(!fileSplitterFetch.bDownOver) ~W-l|-eogz
{ # 0d7
breakWhile = false; f8\DAN
break; ay =B<|!
} L#?mPF
} s",G w]8
if(breakWhile) j115:f
break; ]Q,&7D Ah
F~0iJnF
M6ZXq6J
//count++; KRX\<@
//if(count>4) !3<b#QAXRG
// siteStop(); Jz4;7/
} D9H%jDv
8>G5VhCm~o
yf[1?{iVo
System.err.println("文件下载结束！"); beBv|kI4
} qu.AJ*
catch(Exception e){e.printStackTrace ();} qC=9m[MI
} Adet5m.|[8
JC`;hY
$> ;|
//获得文件长度 s1R#X~d
public long getFileSize() ]heVR&bQ
{ .AQTUd(_
int nFileLength = -1; /3.;sS]B
try{ He$v'87]
URL url = new URL(siteInfoBean.getSSiteURL()); l*(L"]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BUdO:fr
httpConnection.setRequestProperty("User-Agent","NetFox"); ^hsr/|
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jd2 p~W
int responseCode=httpConnection.getResponseCode(); \vx'+}
if(responseCode>=400) P^ht$)Y
{ I]HLWF
processErrorCode(responseCode); nltOX@P-
return -2; //-2 represent access is error Rqbz3h~
} [?=DPE%
W6`_lGTj
A~v[6*~>
String sHeader; Y O|hwhe_
R%~~'/2V
#V)l>
for(int i=1;;i++) j+>[~c;0)
{ -tx%#(?wH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [VLq/lg*
//Utility.log(in.readLine()); I %sw(uoE
sHeader=httpConnection.getHeaderFieldKey(i); fLeHn,*,"
if(sHeader!=null) Lctp=X4
{ 9=FH2|Z
if(sHeader.equals("Content-Length")) mKE'l'9A_
{ oKr= ]p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Unansk
break; dNCd-ep
} z:N?T0b(
} aO}p"-'
else BpGyjoJ2
break; (uX"n`Dk
} Uu@qS
} *NM*
catch(IOException e){e.printStackTrace ();} t|9vb
catch(Exception e){e.printStackTrace ();} \II^&xSF
NGRXNh+
~[kI![
Utility.log(nFileLength); d|`8\fq
UV</Nx)3
APJFy@l}
return nFileLength; t'yh&44_
} )iVuac]E++
TwF.UL@G%
[,;O$j}
//保存下载信息（文件指针位置） "r8N- h/P
private void write_nPos() l^%52m@{
{ &4%78K\
try{ Z2-tDp(I
output = new DataOutputStream(new FileOutputStream(tmpFile)); &_s^C?x
output.writeInt(nStartPos.length); }A[5\V^D*
for(int i=0;i<nStartPos.length;i++) K{9Vyt9,$
{ >L8 &6aU
// output.writeLong(nPos); IGo5b-ds
output.writeLong(fileSplitterFetch.nStartPos); C!nbl+75
output.writeLong(fileSplitterFetch.nEndPos); knzo6
} D51s)?
output.close(); Z^Wv(:Nr
} %tPy]{S..
catch(IOException e){e.printStackTrace ();} [g}0.J`_
catch(Exception e){e.printStackTrace ();} ![eY%2;<
} 1bDAi2 H
a<]vHC7
Ji1#>;&
//读取保存的下载信息（文件指针位置） 5Vdy:l
private void read_nPos() 3[?;s}61
{ *5\'$;Rg
try{ gxJ12' m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h`eHoKJ#w
int nCount = input.readInt(); hFan$W$
nStartPos = new long[nCount]; '*Tt$0#o
nEndPos = new long[nCount]; kIe)ocJg
for(int i=0;i<nStartPos.length;i++) qv>l
{ Eg2SC?5
nStartPos = input.readLong(); {lUaN0O:
nEndPos = input.readLong(); Z0v&AD=
} <u1`o`|-
input.close(); ]3Ibl^J
} iSfRo31
catch(IOException e){e.printStackTrace ();} C1qlB8(Wh>
catch(Exception e){e.printStackTrace ();} RE-y5.kE^
} sPl3JP&s
3hEbM'L
cBU3Q<^
private void processErrorCode(int nErrorCode) ]r%fAmj
{ 3qDbfO[
System.err.println("Error Code : " + nErrorCode); Ls3r( Tf
} )>iPx.hVSS
;?TM_%>
V&/Cb&~Uw
//停止文件下载 >z%WW&Z'
public void siteStop() ~BE=z:
{ I]pz3!On4,
bStop = true; |Ho} D~
for(int i=0;i<nStartPos.length;i++) 5{IbKj|
fileSplitterFetch.splitterStop(); RSw;b.t7
7osHKO<?2
aWP9i&
} M"msLz
} <(xro/
//负责部分文件的抓取 'F:Tv[qx
**FileSplitterFetch.java gNkBHwv
*/ Fiw^twz5
package NetFox; 3Tc90p l*t
FBOgaI83G
Z^%HDB9^
import java.io.*; 0Pt%(^
import java.net.*; (h[. Ie
{Q`Q2'@
QF22_D<.}J
public class FileSplitterFetch extends Thread { 0HQTe>!
j0n.+CO-{
)(c%QWz
String sURL; //File URL |TF6&$>d
long nStartPos; //File Snippet Start Position !kH 1|
long nEndPos; //File Snippet End Position 0,8RA_Ca}
int nThreadID; //Thread's ID l%?()]y
boolean bDownOver = false; //Downing is over 92N`Q}
boolean bStop = false; //Stop identical \J;]g\&I"
FileAccessI fileAccessI = null; //File Access interface |@f\[v9`
ICc:k%wE7
rZ.z!10
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mgodvX
{ x cZF_elt7
this.sURL = sURL; ,E@}=x9p
this.nStartPos = nStart; N-Bw&hEZ
this.nEndPos = nEnd; K!2%8Ej,J
nThreadID = id; 5)0'$Xxqa0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3a}c'$F>_'
} !\OX}kHX5
F ^m;xy
WA*1_
public void run() M!%|IKw
{ THgEHR0,}[
while(nStartPos < nEndPos && !bStop) uU-1;m#N?
{ 23a:q{R
|1e//*
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try{ e)87 & 7
URL url = new URL(sURL); : &~LPmJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A>RK3{7
httpConnection.setRequestProperty("User-Agent","NetFox"); }gE^HH'
String sProperty = "bytes="+nStartPos+"-"; 6!;D],,"#.
httpConnection.setRequestProperty("RANGE",sProperty); k\g:uIsv$
Utility.log(sProperty); QNxxW2+
K(P.i^k
w02C1oGfx
InputStream input = httpConnection.getInputStream(); 5v=e(Ph+
//logResponseHead(httpConnection); @Q&k6.{4Z
H7meI9L
a6;5mx
byte[] b = new byte[1024]; &^Gp
int nRead; C<w&mFozL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cJM.Q_I}Y
{ ,e GF~
nStartPos += fileAccessI.write(b,0,nRead); .*J /F$
//if(nThreadID == 1) PR,8c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a(G}<
} `lt[Q>Z
: JSuC
4[Wwm
Utility.log("Thread " + nThreadID + " is over!"); ,pVe@d'
bDownOver = true; $H&:R&Us
//nPos = fileAccessI.write (b,0,nRead); A!}Ps"Z
} ::-*~CH)
catch(Exception e){e.printStackTrace ();} fP$rOJ)P
} ;Sp/N4+
} H6/gRv@
FC]n?1?<(
A5_r(Z-5
//打印回应的头信息 Ue"pNjd|
public void logResponseHead(HttpURLConnection con) YgjN*8w\
{ 9o3?
for(int i=1;;i++) +wI<w|!
{ |=V~CQ]
String header=con.getHeaderFieldKey(i); |.-Muv
if(header!=null) vskp1Wi(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); upZf&4 I8
Utility.log(header+" : "+con.getHeaderField(header)); &VG
else <|w(Sn
break; d"Zyc(Jk
} c: (nlYZ
} #]Jg>
}d5~w[
O]Yz7
public void splitterStop() r@ !
{ H?V b
bStop = true; 6)>otB8)J
} ofPv?_@
rZ2cC#
_6g(C_m'T?
} s=556
Py?Q::
$ ?|;w,%I
/* =hY/Yr%P
**FileAccess.java 4U u`1gtz
*//文件访问(定位，写) 2^f7GP
package NetFox; )CgH|z:=b
import java.io.*; imKMPO=
<Pi#-r.,
a|4Q6Ycu
public class FileAccessI implements Serializable{ sk AF6n
{i}E)Np
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k+Z2)j"
RandomAccessFile oSavedFile; [khXAf1{Q
long nPos; g}L>k}I?!W
(A "yE4rYK
S,Tc\}
public FileAccessI() throws IOException Aq\K N.
{ Ch:EL-L
this("",0); nlaW$b{=
} P]armg%
b[:{\!I
_KkP{g,Y
public FileAccessI(String sName,long nPos) throws IOException xV=Tmu6l
{ usC$NVdm
oSavedFile = new RandomAccessFile(sName,"rw"); '}"&JO~vPj
this.nPos = nPos; ?/myG{E
oSavedFile.seek(nPos); 8pZOgh
} ;|:R*(2
*%E\mu,,c
c]/S<w<
public synchronized int write(byte[] b,int nStart,int nLen) xErb11
{ ;uzLa%JQ
int n = -1; E]=>@EX
try{ J;4aghzY
oSavedFile.write(b,nStart,nLen); jx2{kK
n = nLen; 14 (sp
} @7KG0<]h
catch(IOException e) 8)ng> l
{ ?GW}:'z
e.printStackTrace (); ;~'&m
} vhcp[=e :
M}Xf<:g)
[AA}P/iW
return n; VKf&}u/
} /'b7q y
d[XMQX
"\=Phqw
} Lj3Pp$h
U]@?[+I0]
,]]*}4[r
/* 8_"NF%%(n
**SiteInfoBean.java (OA4H1DL^
*/ )4m`Ya,E3
package NetFox; kg\8 (@h]
<Y2$'ETD
4u"Bll
public class SiteInfoBean { D2=zrU3Y64
b};o:
Rd|8=`)
private String sSiteURL; //Site's URL OHrzN']
private String sFilePath; //Saved File's Path '$?!>HN4
private String sFileName; //Saved File's Name .J O1kt
private int nSplitter; //Count of Splited Downloading File j#Tl\S!m.I
)ax>*
/?($W|9+l
public SiteInfoBean() ;mvVo-r*q
{//nSplitter的缺省值为5 +.OdrvN4)
//default value of nSplitter is 5 HrfS^B
this("","","",5); 9%1J..c
} O?cU6u;W
b4WH37,lA
?_cOU@n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lk[Y6yE
{ -'SA&[7dP
sSiteURL= sURL; #qpP37G
sFilePath = sPath; To5hVL<Ex"
sFileName = sName; Z*Gf`d:
this.nSplitter = nSpiltter; z?( b|v
x0:BxRx*
5t"FNL <(M
} DfP-(Lm)
QWEE%}\3}
:2&"ak>N
public String getSSiteURL() Rn]xxa'
{ `E?0jQ
return sSiteURL; -a&<Un/
} ZfK[o{9>
!?/:p.
P^48]Kj7
public void setSSiteURL(String value) 7 )rL<+
{ _53~D=
sSiteURL = value; mt`CQz"_
} \"Y,1in#
RjVmHhX
|_>^vW1f
public String getSFilePath() q=V'pML
{ x!\q69ndv
return sFilePath; Q2uV/M1?
} [/%N2mj
e}S+1G6r)
f'H|K+bO
public void setSFilePath(String value) >]z^.U7=
{ Z6A-i@
sFilePath = value; nSC2wTH!1
} F= %A9b_a
?Ve IlD
`fTM/"
public String getSFileName() ,"XiI$Le
{ O#^H.B
return sFileName; c38XM]Jeq
} 4=MjyH|[Jx
CgrQ"N5
J}:.I>
public void setSFileName(String value) XNv2xuOcJ
{ ^W,5A;*3
sFileName = value; (6Z^0GL
} +E_yEH7_)
{svo!pN:
mPk'a
public int getNSplitter() XW" 0:}`J
{ n2hV}t9O
return nSplitter; >([,yMIY
} 3m`>D e
~IS8DW$;
9;?u%
public void setNSplitter(int nCount) ~"CGur P
{ }Mt1C~{(
nSplitter = nCount; 7K:V<vX5
} HP1QI/*v
} (rkg0
X3X_=qzc
G9 O6Fi
/* ow.!4kx{d
**Utility.java wz*iwd-
*/ (Y@T5-!D
package NetFox; $?G@ijk,
|f#hGk6
5;UIz@BJ
public class Utility { -6HwGfU
xI{4<m/0N
q`b6if"
public Utility() Z,A$h>Z
{ e12QYoh
,_I rE
I/MY4?(T
} bYnq,JRA
$2?AJ/2r$b
//线程睡眠 E)gD"^rex
public static void sleep(int nSecond) R=lw}jH[Z
{ ;*M@LP{*L
try{ "J1A9|
Thread.sleep(nSecond); ?<TJ}("/
} 49$<:{~
catch(Exception e) 7upko9d/
{ hx$61E=
e.printStackTrace (); 1x:W 3.
} VP~2F E
} d?2ORr|m=
Cp6S2v I
//日志 T8x)i\<
public static void log(String sMsg) Og/aTR<;=
{ $`E?=L`$
System.err.println(sMsg); q[,p#uJ]
} <gkE,e9
J**(7d
xR/CP.dg
public static void log(int sMsg) K8;SE!
{ ,,gMUpL7_8
System.err.println(sMsg); iZ-R%-}B
} .ybmJU*Hg
} w`)5(~b
W2 -%/
nn_O"fZi
/* ]?tRO
**TestMethod.java -WlYHW
*/ c$Kc,`2m7
package NetFox; :o>=^N
E EDFyZ
Y 3BJ@sqz
public class TestMethod { $3^M-w
\yr9j$
p%I'd^}.!
public TestMethod() i6'=]f'{
{ ///xx/weblogic60b2_win.exe /Sw~<B!8N
try{ EAGvP&~P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hv|a8=U!R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =:gKh
SiteFileFetch fileFetch = new SiteFileFetch(bean); QnWE;zN[7A
fileFetch.start(); 5H0qMt P
} @:C)^f"
catch(Exception e){e.printStackTrace ();} :>0ywg
pAE (i7
yV(#z2|
} 79v+ze
nK1eh@a9Qv
8tx*z"2S
public static void main(String[] args) *[Z`0AgP
{ >GGM76vB=,
new TestMethod(); !p&<.H_
} `Nx@MPo
} Z7a@$n3h
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