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)); Oj,v88=
} Q&@e,7]V+
for(int i=0;i<nEndPos.length-1;i++) zAkF:^#Y
{ O}3|UI!`
nEndPos = nStartPos[i+1]; !SPu9:
} B'D\l\w
nEndPos[nEndPos.length-1] = nFileLength; Gv+$7{
} ;xQNa}"V
} >>b <)?3Rv
c.eUlr_{
z4iTf8
//启动子线程 5kx-s6`!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !x$6wzKa
for(int i=0;i<nStartPos.length;i++) MfU0*nVF~
{ ]I[\Io1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H2JKQm_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [q!/YL3%
nStartPos,nEndPos,i); Gpf9uj%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {~"fq.h!M
fileSplitterFetch.start(); Q`m9I
} xa[)fk$6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _C54l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !Pc&Sg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }`uFLBG3
nEndPos = " + nFileLength); fWz=bJ"V
// fileSplitterFetch[nPos.length-1].start(); eq6>C7.$
VxAG=E
V]5MIiNl
//等待子线程结束 oiTSpd-
//int count = 0; h3rVa6cxM
//是否结束while循环 QF4)@ r{2x
boolean breakWhile = false; Aryp!oW
?P%-p
% 4Gt^:J"
while(!bStop) d^+0=_[PmK
{ Mpx98xcO
write_nPos(); Kn*LwWne
Utility.sleep(500); PSHzB! H=n
breakWhile = true; <f9a%`d
[C`LKA$t
<]f{X<ef
for(int i=0;i<nStartPos.length;i++) cw/E?0MWb
{ v83@J~
if(!fileSplitterFetch.bDownOver) Eyq4w
{ X6Q\NJ"B
breakWhile = false; H{4_,2h=m
break; :SD#>eD0
} "DC L Z
} g-4j1yJV<
if(breakWhile) }B ?_>0
break; M)"'Q6ck=
@gnLY
u\q(v D.
//count++; O~#A )d6
//if(count>4) 'mTQ=1
// siteStop(); _-|+k
} vyvb-oz;u
L]*5cH
D4O^5?F)|
System.err.println("文件下载结束！"); )8`i%2i=
} v|R#[vtFd
catch(Exception e){e.printStackTrace ();} 8bdx$,$k
} Gzc`5n{"
V<ii
s=>^ 8[0O
//获得文件长度 "BZL*hHq
public long getFileSize() OK(xG3T
{ ~X(2F#{<{
int nFileLength = -1; AD~_n^
try{ B8~bx%)3T
URL url = new URL(siteInfoBean.getSSiteURL()); zyB>peAp6j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4YgO1}%G
httpConnection.setRequestProperty("User-Agent","NetFox"); ~wQ M ?h
'Ll'8 ps
~7wLnB
int responseCode=httpConnection.getResponseCode(); wlFK#iK
if(responseCode>=400) FA{'Ki`
{ ;]l`Q,*OXb
processErrorCode(responseCode); =wMq!mBd
return -2; //-2 represent access is error uhU'm@JZ
} H6hhU'Kxf8
9\VV++}s>o
>mj WC) U
String sHeader; d*dPi^JjC
vDIsawbHD
QIfP%,LT
for(int i=1;;i++) 48_( 'z*>
{ hd W7Qck"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?-'GbOr!
//Utility.log(in.readLine()); <m,bP c :R
sHeader=httpConnection.getHeaderFieldKey(i); N%S|Ey@f
if(sHeader!=null) bPIo9clq
{ 9 ^=kt 2[
if(sHeader.equals("Content-Length")) 8Oa+,?<0x
{ (6i4N2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?u5jXJ0L
break; u%5 ,U-
} \A6}=
} ?e\u_3-9
else A{Qo}F<*
break; a-lF}P\
} OQVo4yl"
} IEe;ygL#
catch(IOException e){e.printStackTrace ();} MaLH2?je^n
catch(Exception e){e.printStackTrace ();} 'Hsd7Dpi}
TQykXZ2Yb)
0J6* U[
Utility.log(nFileLength); ?:6w6GwAA
Bkg./iP5x
N|%X/UjZ2.
return nFileLength; `7oYXk
} <Ira~N
Z&n#*rQ7[
|Yv,zEY)
//保存下载信息（文件指针位置） 3bT?4
private void write_nPos() V`rxjv}!
{ [OS&eK 8
try{ T%A"E,#
output = new DataOutputStream(new FileOutputStream(tmpFile)); eH~T PH
output.writeInt(nStartPos.length); o7^0Lo5Z?
for(int i=0;i<nStartPos.length;i++) lQv(5hIm
{ c9djBUAk&
// output.writeLong(nPos); fNV-_^,R9
output.writeLong(fileSplitterFetch.nStartPos); *;l[|
output.writeLong(fileSplitterFetch.nEndPos); )2 b-3lz
} \}AJ)v*<
output.close(); $wbIe"|
} R5\|pC
catch(IOException e){e.printStackTrace ();} -wVuM.n(Z
catch(Exception e){e.printStackTrace ();} eh8lPTKil
} {{AZW
hxt;sQAo{
q3`~uTzk
//读取保存的下载信息（文件指针位置） 8T8]gM
private void read_nPos() `NNP}O2
{ 4ves|pLET
try{ j=c< Lo`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $W9dUR0
int nCount = input.readInt(); a*t>Ks'C
nStartPos = new long[nCount]; ZiRCiQ/?
nEndPos = new long[nCount]; k"6v& O
for(int i=0;i<nStartPos.length;i++) ?J-D6;
{ 03_M+lv
nStartPos = input.readLong(); AW'$5NF>
nEndPos = input.readLong(); wYDdy gS
} )@<HG$#
input.close(); ?X Rl\V
} !}sF#
catch(IOException e){e.printStackTrace ();} Oc-ia)v1G
catch(Exception e){e.printStackTrace ();} _:FD#5BZ1
} E,fbIyX
u>:j$@56
+O)ZB$w4
private void processErrorCode(int nErrorCode) +??pej]Rp
{ {R/e1-;
System.err.println("Error Code : " + nErrorCode); |XMWi/p
} iBmvy7S?
B5+$VQ
9i D&y)$"
//停止文件下载 D&pp <
public void siteStop() 1tTY)Evf
{ kh8 M=
bStop = true; h>p,r\X
for(int i=0;i<nStartPos.length;i++) k5*Z@a
fileSplitterFetch.splitterStop(); A|GsbRuy
7%G&=8tq
u$X =2u:P
} I}m>t}QRI_
} u68ic1
//负责部分文件的抓取 c~}FYO$
**FileSplitterFetch.java k=G c#SD5_
*/ Cq3Au%7
package NetFox; cQsSJBZ[v5
]:m4~0^#-(
vu&ny&=`
import java.io.*; [^XD@
import java.net.*; 5DO}&%.xt
Vy^mEsQC+h
@1U6sQ
public class FileSplitterFetch extends Thread { [z6P]eC7
:Zo^Uc:*w
b<[]z,
String sURL; //File URL eR/X9<
long nStartPos; //File Snippet Start Position P.(z)!]
long nEndPos; //File Snippet End Position 0DN&HMI#
int nThreadID; //Thread's ID AS0mMHJk
boolean bDownOver = false; //Downing is over rB|4
boolean bStop = false; //Stop identical jo<Gf 5
FileAccessI fileAccessI = null; //File Access interface 6/vMK<Fz9
!& >LLZ
[E"3?p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nFe
{ yo$A0Ti!w
this.sURL = sURL; -y[y.#o
this.nStartPos = nStart; r"p"UW9og
this.nEndPos = nEnd; vE)d0l"
nThreadID = id; R/ x-$VJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QUg<~q)Oq
} Hl*#iUq
lTFo#p_(
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public void run() 07:h4beT
{ wRq f'
while(nStartPos < nEndPos && !bStop) XhN?E-WywQ
{ AgB$ w4
r5+MjR
%o`Cp64`Q
try{ #qJ6iA6{
URL url = new URL(sURL); +vPCr&40
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =#wE*6T9
httpConnection.setRequestProperty("User-Agent","NetFox"); Ri}JM3\J
String sProperty = "bytes="+nStartPos+"-"; ;!OME*?m<
httpConnection.setRequestProperty("RANGE",sProperty); V#c=O}
Utility.log(sProperty); ;<%d^
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]eX(K5 A
InputStream input = httpConnection.getInputStream(); rP/W,! 7:K
//logResponseHead(httpConnection); H>"P]Y)oX
wy:euKB~
'b+ Tio
byte[] b = new byte[1024]; `8TL*.9
int nRead; E~8J<gE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Eh[NKgYL
{ u/wWD@,
nStartPos += fileAccessI.write(b,0,nRead); ZW 5FL-I
//if(nThreadID == 1) nE:Wl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GkKoc v
} FY]Et=p
~dLe9-_9
db3.X~Cn#s
Utility.log("Thread " + nThreadID + " is over!"); 'lgS)m
bDownOver = true; W;U<,g '
//nPos = fileAccessI.write (b,0,nRead); N'|9rB2e
} g%D.sc)69
catch(Exception e){e.printStackTrace ();} 0 4oMgH>Vd
} 5p/.( |b,
} 5z" X>!?^
^Nysx ~6
s5X51#J#~
//打印回应的头信息 En0hjXa
public void logResponseHead(HttpURLConnection con) 0,iG9D7
{ ?:F Jc[J
for(int i=1;;i++) Kn2W{*wD
{ P%<MQg|k`
String header=con.getHeaderFieldKey(i); Ac/LNqIs
if(header!=null) 1z@ ncqe
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5o0H7k]
Utility.log(header+" : "+con.getHeaderField(header)); 18y'#<X!
else |voZ0U
break; lO}I>yo}\
} W=,]#Z+M;
} QR$m i1Vv\
0iz\<' p
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public void splitterStop() ={{q_G\WD
{ 4=|oOIhgb
bStop = true; yWi?2
} $tK/3
W@~a#~1O
\JNWL yw
} K{FBrh
0X%#9s~
i^rHZmT
/* 5[^Rf'wy
**FileAccess.java BIT<J5>
*//文件访问(定位，写) x![ut
package NetFox; 0rc'SEl
import java.io.*; jfZ)
_~!c%_
\u6/nvZ]N
public class FileAccessI implements Serializable{ 6{ pg^K
;]2d%Qt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Nh6!h%
RandomAccessFile oSavedFile; a3:1`c/~\
long nPos; D5!I{hp"
|(9l_e|
Q*/jQC
public FileAccessI() throws IOException 5"Y:^_8
{ hP jL
this("",0); ~e+pa|lO
} EsLtC5]
`L.nj6F
Sqla+L*
public FileAccessI(String sName,long nPos) throws IOException {%X[Snv
{ M|7{ZE`Y
oSavedFile = new RandomAccessFile(sName,"rw"); OL623jQX
this.nPos = nPos; nB%[\LtZ?
oSavedFile.seek(nPos); }]j#C
} IZxr;\dq6
\Pd>$Q
7#9fcfL
public synchronized int write(byte[] b,int nStart,int nLen) ~8[`(/hj
{ j8ac8J,}c
int n = -1; RNX>I,2sh
try{ CbT ;#0
oSavedFile.write(b,nStart,nLen); wd Di5-A4
n = nLen; tj tN<y
} &lB>G[t
catch(IOException e) +)7h)uq
{ x|3G}[=
e.printStackTrace (); ^]$rh.7&
} t;lK=m|
4n2*2 yTg
44UN*_qG
return n; n5?7iU&JIo
} prVqV-S6TY
;oRgg'k<
ABhQ7 x|
} p1,.f&(f
IVG77+O# }
7*47mJyc
/* }kk[lvhJ
**SiteInfoBean.java N!13QI H
*/ `W4Is~VVv
package NetFox; l/bZE.GJ
K)9f\1\
V_T~5%9Fy
public class SiteInfoBean { qWI8 >my11
*BQy$dfE
Aj@t*3
private String sSiteURL; //Site's URL Qf|c^B
private String sFilePath; //Saved File's Path e]smnf
private String sFileName; //Saved File's Name *GM.2``e
private int nSplitter; //Count of Splited Downloading File SCXtBZ`.G
Q% J!
<GoZ>
public SiteInfoBean() .IORvP-M&
{//nSplitter的缺省值为5 f_> lz
//default value of nSplitter is 5 c)17[9"
this("","","",5); R9%"Kxm
} `AhTER
AJt4I W@
iKgH :[j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E^V4O l<
{ NKRH>2,
sSiteURL= sURL; $(pVE}J
sFilePath = sPath; ~"WN4
sFileName = sName; ] U[4r9V
this.nSplitter = nSpiltter; oo!JAv}~
}zHG]k,j
{OW.^UIq^
} BE," lX
2r#W#z%vS
<VmEXJIk
public String getSSiteURL() `qj24ehc
{ c]/&xRd
return sSiteURL; ?uqPye1fc
} w0fFm"A|W
O@,9a~Ghd
Q E*`#r#e
public void setSSiteURL(String value) K=;oZYNd
{ uJL[m(G
sSiteURL = value; Z~DR,:
} }&IOBYHVDo
Uj>bWa`
'E1m-kJz
public String getSFilePath() a &tl@y1
{ -l q,~`v
return sFilePath; {us"=JJVN
} Lz}mz-N
N uq/y=
wnbKUlb
public void setSFilePath(String value) Ea?u5$>gY"
{ i^&^eg'.5
sFilePath = value; lag%}^
} 5U%a$.yr
)zq sn
Vw b6QIs
public String getSFileName() /}RW~ax
{ (T2\
return sFileName; @#&y
} C(5B/W6
{~eVZVv
%n>*jFC
public void setSFileName(String value) @ykM98K
{ I0C$
sFileName = value; [V.#w|n
} )nA fT0()0
^Euqy,8}
_9b;8%?Yf
public int getNSplitter() :/FT>UCL
{ OG}m+K&<
return nSplitter; p*"H&xA@
} tD\%SiTg=b
%P-z3 0FHp
|fg{Fpc
public void setNSplitter(int nCount) uY Y{M`
{ %v 1NDhaXz
nSplitter = nCount; 53X5&Bwh
} ^jZ4tH3K
} SpiI9)gp
RS[>7-9
X\'+);Z
/* Kq2,J&Ca3
**Utility.java cAc>p-y%
*/ N?krlR
package NetFox; @F0+t;
rP7f~"L
@b"J FB|
public class Utility { `f+l\'.s
e`Vb.E)
u.L{3gkT
public Utility() zQ~8(E]Rf
{ uPveAK}h
V.Ki$0>
%,[p[`NRYR
} H8'_.2vwX
D\i8WU
//线程睡眠 DZ~qk+,I
public static void sleep(int nSecond) V50FX}i
{ LHJjPf)F
try{ .l(t\BfE~
Thread.sleep(nSecond); Ud[Zv?tA:
} \w\{x0u
catch(Exception e) a}MSA/K(
{ WaYT7 :
e.printStackTrace (); COk;z.Kn
} 1Ydym2
} 6`Af2Y_
eW^_YG%(
//日志 4` zfrT^
public static void log(String sMsg) ;OynkZs)
{ *%wfR7G[B
System.err.println(sMsg); sM$gfFx
} .,5N/p"aV
a+Z95~*sZ"
W_ hckq.
public static void log(int sMsg) fd} Ul
{ |T@\-8Ok
System.err.println(sMsg); ^+20e3 ~Y
} 1JXa/f+
} 4tv}V:EO
vPA {)l\K
c3$h-M(jVJ
/* =UW! 7OzC
**TestMethod.java t^zmvPDK
*/ dJ}E,rW}
package NetFox; 5??\[C^"}
9dFSppM
|p"E0av
public class TestMethod { ` kG}NJf
J` J^C
kt*""&R
public TestMethod() _H+|Ic
{ ///xx/weblogic60b2_win.exe 5VG[FY6Pl
try{ g-Y2U}&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CZL:&~l1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v2uyn
SiteFileFetch fileFetch = new SiteFileFetch(bean); g:sn/Zug]
fileFetch.start(); 6*n<emP
} SuU_psF
catch(Exception e){e.printStackTrace ();} zrg#BXj7
_b8?_Zq
8I`t`C/4
} \Gk4J<
a*Oc:$
r)G^V&96
public static void main(String[] args) tgPx!5U
{ Rr|&~%#z
new TestMethod(); {:;599l
} wtY*{m2
} D+ )R_
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