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)); #`=>Mza
} WA1yA*S
for(int i=0;i<nEndPos.length-1;i++) \ZhkOl
{ 0S4Y3bac&
nEndPos = nStartPos[i+1]; n[qnrk*3 %
} @jjxgd'%&
nEndPos[nEndPos.length-1] = nFileLength; 92R,o'#
} }.U(Gxu$
} OC-d5P
wu11)HFL|z
7J`v#
//启动子线程 ;;rx)|\<R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^&y*=6C
for(int i=0;i<nStartPos.length;i++) t5S|0/f
{ J}4RJ9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &'i>d&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p\#;(pf}s
nStartPos,nEndPos,i); 'rFLG+W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &e3}Vop
fileSplitterFetch.start(); yw%ES
} L0H^S)g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :SO4@JT{W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -:Fr($^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }?Pa(0=U
nEndPos = " + nFileLength); |0>rojMq
// fileSplitterFetch[nPos.length-1].start(); P s|[
/NR*<,c%
$7xfLS8Vo
//等待子线程结束 uh#E^~5S
//int count = 0; a #s Nd
//是否结束while循环 <;>k[P'
boolean breakWhile = false; $Jn.rX0}$
xiQc\k$
OEzSItAI/[
while(!bStop) xO%yjG=
{ >b#CR/^z
write_nPos(); X}h}3+V
Utility.sleep(500); fpjFO&ML
breakWhile = true; |F'eT 4
e.(d?/!F_
ygm6(+
for(int i=0;i<nStartPos.length;i++) n}1hmAhZ
{ qh&KNJ>1
if(!fileSplitterFetch.bDownOver) +!`$(
{ @m:' L7+
breakWhile = false; P@n rcgM.
break; \k6OP
} ,If"4C!w
} BVH)!]m0
if(breakWhile) qX6zk0I a
break; "]'W^Fg
x 0vW9*&
i!JSEQ_8
//count++; $Op:-aW&
//if(count>4) 8Jp?@qt=$
// siteStop(); prIJjy-F
} Oq3t-omXS
!^1oH**
B%))HLo'
System.err.println("文件下载结束！"); (U.VCSn
} nHfAx/9!
catch(Exception e){e.printStackTrace ();} h]|2b0
} K&dc< 4DC
u8<Fk !
uV'C_H
//获得文件长度 ,g|ht%"
public long getFileSize() eUgKwu;
{ %\B?X;(
int nFileLength = -1; i !SN"SY
try{ o@} qPvt0
URL url = new URL(siteInfoBean.getSSiteURL()); #0#6eT{-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5$$]ZMof
httpConnection.setRequestProperty("User-Agent","NetFox"); A9[D.W9>
w#bdb;
'=(yh{W
int responseCode=httpConnection.getResponseCode(); )D]LPCd[
if(responseCode>=400) T0\[": A
{ 3A\Hiy!{F
processErrorCode(responseCode); M[R'
return -2; //-2 represent access is error I;P!
} $"=0{H.?
^*~4[?]S
*iPBpEWC
String sHeader; d+8|aS<A
Aj>
)hK;27m4
for(int i=1;;i++) ,qdZ6bv,]|
{ H a`V"X{}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z$)jPDSr
//Utility.log(in.readLine()); B|;?#okx
sHeader=httpConnection.getHeaderFieldKey(i); 9!D c=
if(sHeader!=null) :{Iv ]d
{ mT1Q7ta*P
if(sHeader.equals("Content-Length")) n{c-3w.uD
{ |B),N f|a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b&pL}o?/k
break; b3-+*5L
} +gb"} cN
} &23t/`
else =VZ0+Yl
break; ve(@=MJ
} e#tWQM3
} ZQ#AEVI,
catch(IOException e){e.printStackTrace ();} cW^u4%f't'
catch(Exception e){e.printStackTrace ();} q&wv{
~~WX#Od*$
f{D~ZC.*
Utility.log(nFileLength); kAoh#8=
*AYjMCo
!t&C,@Ox
return nFileLength; u$x'P <b
} o-]8)G>~M
B :1r;8{j
\&Oc}]
//保存下载信息（文件指针位置） 42DB0+_wz
private void write_nPos() ob(~4H-
{ U }}E E~W
try{ NX<Q}3cC
output = new DataOutputStream(new FileOutputStream(tmpFile)); n(Ry~Xu_
output.writeInt(nStartPos.length); 9z?B@;lMc
for(int i=0;i<nStartPos.length;i++) FzFP 0
{ FOX0
// output.writeLong(nPos); ~T'$gl
output.writeLong(fileSplitterFetch.nStartPos); ')E4N+h/
output.writeLong(fileSplitterFetch.nEndPos); 88atj+N]
} Otm7j>w
output.close(); "I[uD)$
} {_J1m&/
catch(IOException e){e.printStackTrace ();} !f8]gTzN
catch(Exception e){e.printStackTrace ();} 4({Wipd
} ew8Manx
Hb9r.;r<EW
'jU;.vZex
//读取保存的下载信息（文件指针位置） v;R+{K87
private void read_nPos() Q .cL1uHc
{ iA+zZVwO
try{ }cI _$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p!cNn7{;
int nCount = input.readInt(); to'O;f">n
nStartPos = new long[nCount]; D?? \H\
nEndPos = new long[nCount]; CK} _xq2b
for(int i=0;i<nStartPos.length;i++) kS(v|d
{ aaesgF
nStartPos = input.readLong(); C6}`qD
nEndPos = input.readLong(); T:EUI]
} Jd/XEs?<q
input.close(); K;(t@GL?
} JuXuS
catch(IOException e){e.printStackTrace ();} dw< b}2
catch(Exception e){e.printStackTrace ();} !tv+,l&L
} 0[SrRpD
BQ77n2(@
tumYZ)nW
private void processErrorCode(int nErrorCode) i.>d#S
{ >]l7AZ:,
System.err.println("Error Code : " + nErrorCode); Gv}~
} 1cPjgBxv#
'tzN.p1O
Q!}LtR$
//停止文件下载 hk+"c^g:j<
public void siteStop() si>gYO
{ ndB*^nT
bStop = true; >U'gQS?\]
for(int i=0;i<nStartPos.length;i++) ~px)Jd
fileSplitterFetch.splitterStop(); WzO[-csy
V]A*' ke/
1ba* U~OEg
} ?O#,|\v?]
} hvU\l`m
//负责部分文件的抓取 $3 ~/H"K
**FileSplitterFetch.java !5h@uar
*/ I)cA:Ip
package NetFox; PsoW:t
Z <vTr6?
3gU*,K7
import java.io.*; 6I$:mHEhd
import java.net.*; /c-%+Xd
nL-kBW Ed>
-&_;x&k /
public class FileSplitterFetch extends Thread { _'DZoOH|VE
iQ_^MzA
}{m.\O
String sURL; //File URL Z%O>|ozpq
long nStartPos; //File Snippet Start Position wDS(zG
long nEndPos; //File Snippet End Position ( G#W6
int nThreadID; //Thread's ID a$P$Ngi?S
boolean bDownOver = false; //Downing is over |+(Hia,X
boolean bStop = false; //Stop identical ^B7C8YP
FileAccessI fileAccessI = null; //File Access interface QDJ:LJz\
w`r)B`!g
#`{L_n$c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j+>&~
{ ?;)F_aHp
this.sURL = sURL; :~+m9r
this.nStartPos = nStart; w?zY9Fs=s
this.nEndPos = nEnd; tR% &.,2
nThreadID = id; B< BS>(Nr>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 14;lB.$p
} |9cSG),z
XP!7@:
y@Q? guB
public void run() naB`@
{ `tZ`a
while(nStartPos < nEndPos && !bStop) /QCyA%y
{ H@hHEzO
Qp]-4%^Vz
1brKs-z
try{ b!xm=U
URL url = new URL(sURL); ^5d9n<_xnQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1*J#:|({(
httpConnection.setRequestProperty("User-Agent","NetFox"); `di/nv)
String sProperty = "bytes="+nStartPos+"-"; b9@VD)J0E
httpConnection.setRequestProperty("RANGE",sProperty); \H5{[ZUn
Utility.log(sProperty); VyL|d^'f_
J?N9*ap)
o@g/,V $
InputStream input = httpConnection.getInputStream(); E?Ofkc$q
//logResponseHead(httpConnection); j8"2K^h=
/Jci1o
9 ]W4o"
byte[] b = new byte[1024]; bB|P`lL
int nRead; "sU ~|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [O"8Tzr
{ qo"_w%{
nStartPos += fileAccessI.write(b,0,nRead); z("Fy
//if(nThreadID == 1) Um'r6ty
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !4l\*L
} ``4lomz>
gC qQ~lWZ
Jf=$h20x
Utility.log("Thread " + nThreadID + " is over!"); nzK"eNDN.
bDownOver = true; 3?R QPP
//nPos = fileAccessI.write (b,0,nRead); :},/D*v
} .JkF{&=B
catch(Exception e){e.printStackTrace ();} 86,$ I+
} uuMHD{}?}
} S0<m><|kl
Vz,2_QJ
hu+% X.F4
//打印回应的头信息 lm;G8IP`
public void logResponseHead(HttpURLConnection con) 15^5yRXC
{ CAD:ifV
for(int i=1;;i++) X@n\~[.B
{ AE"E($S`
String header=con.getHeaderFieldKey(i); vz_ZXy9Z
if(header!=null) kbkq.fYr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #Qp.O@e
Utility.log(header+" : "+con.getHeaderField(header)); )c$)am\I{
else W=k%aB?p
break; Ly$s0.!
} z.7'yJIP#
} )bGd++2
)4P5i b
Qe )#'$T
public void splitterStop() axW4cS ?
{ hj.Du+1
bStop = true; sR1 &2hB
} br9`77J8
aab?hR
HKdR?HM1
} !bHM:!6^
G$D6#/rR
4U*uH
/* H}$hk
**FileAccess.java An%V>a-[
*//文件访问(定位，写) >WW5Apy[
package NetFox; UUt631
import java.io.*; p3NTI/-
-)Y?1w
F^]?'`7md
public class FileAccessI implements Serializable{ :tA|g
Um$a9S8b&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ymsqJ
RandomAccessFile oSavedFile; Mwdw7MZ"S
long nPos; 69v[*InSd
]cv|A^
0+\~^
public FileAccessI() throws IOException %T&#JF+;
{ YTco;5/
this("",0); ^<e"OV
} o\luE{H .?
(qP !x 2j
0P_Y6w+
public FileAccessI(String sName,long nPos) throws IOException afZPju"-
{ )^&)f!f
oSavedFile = new RandomAccessFile(sName,"rw"); LQMVC^G
this.nPos = nPos; W`PK9juu
oSavedFile.seek(nPos); W&>+~A
} pP'-}%
z^f-MgWG
CDcs~PR@B
public synchronized int write(byte[] b,int nStart,int nLen) h,@x5q>g
{ Wb4%=2Qn
int n = -1; \4SFD3$&
try{ 3\,TI`^C
oSavedFile.write(b,nStart,nLen); Xm`K@hJ@
n = nLen; JHf}LZu
} iDO~G($C
catch(IOException e) "*@iXJxv5
{ y(RbW_ ?
e.printStackTrace (); b*6c.
} NRKAEf_#w
uREc9z`Q'
~P5!VNJ;r
return n; Ej1 [ry
} VmTk4?V4
b)u9#%Q
d]e`t"Aj
} <C4^Vem
e<^tY0rR&
<,0&Ox
/* 1F5F2OT$8
**SiteInfoBean.java 33\b@F7b
*/ `bZ_=UAb
package NetFox; RWBmQg^]X
B`hxF(_p/
LFSOHJj
public class SiteInfoBean { UhCd,
E"Xi
xiRTp:>
private String sSiteURL; //Site's URL 6x@-<{L
private String sFilePath; //Saved File's Path d*3R0Q|#{
private String sFileName; //Saved File's Name ?=IbiT
private int nSplitter; //Count of Splited Downloading File -T{~m6
gr=ke #
hJ:Hv.{`)W
public SiteInfoBean() O!f*@
{//nSplitter的缺省值为5 ]?)zH:2)
//default value of nSplitter is 5 PJAir8
this("","","",5); kX1hcAa
} nbpN+a%
7<.f&1MgI
=GR Em5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '~ ]b;nA
{ GZ'hj_2%<
sSiteURL= sURL; <6apv(2a
sFilePath = sPath; g6W.Gl"5\w
sFileName = sName; y+:<
this.nSplitter = nSpiltter; cDTDim1F
9I RE@c
#8/Z)-G
} dy`~%lX?
1xtbhk]D
Vxgc|E^J
public String getSSiteURL() ^U_jeAuk8[
{ kLD)<D
return sSiteURL; ;pB?8Z
} E/GI:}YUy_
nMc-kyl{
9J]LV'f7
public void setSSiteURL(String value) G>_ZUHdI
{ &P{%C5?{
sSiteURL = value; d&'6l"${
} @pkozE-
&(.ZHF
Ra*9d]N@
public String getSFilePath() BLJ-'8G
{ "J{,P9P6
return sFilePath; 5d4-95['_
} -=qmYf
fCVSVn"o
jN {ED_
public void setSFilePath(String value) b'{D4/
{ P7Y[?='v
sFilePath = value; \|&5eeE@
} )O&$-4gL'
U&eLj"XZ
Ns9g>~
public String getSFileName() MoFZ
{ |]]fcJOBP
return sFileName; gVl#pVO`N
} h'jnc.
yWK[@;S]%
IaF79}^
public void setSFileName(String value) d~_OWCg`
{ l/I W"A
sFileName = value; iCEX|Tj;
} p' gv5\u[w
<n`|zQ
!{3pp
public int getNSplitter() )t.q[O`
{ QTyl=z7
return nSplitter; $ `ho+
} . }1!MK5
BW*zj=N%
}gn0bCJy
public void setNSplitter(int nCount) -FPl",f=r
{ +<|w|c
nSplitter = nCount; B=p'2lla
} ><DE1tG
} JEd/j zR(
v]1rH$
6RtpB\hq
/* '\;tmD"N5#
**Utility.java 9(I4x]`
*/ [zfGDMG&
package NetFox; KVntBe]I
NSkI2>+P
P6?Q;-\q0
public class Utility { w7W-=\Hvh
#nd,cn
](ninSX1w
public Utility() k{#:O=
{ D *tBbV
5u!cA4e"
doa$ ;=wg
} Q7s1M&K
{%$=^XO
//线程睡眠 2,fB$5+
public static void sleep(int nSecond) R3<+z
{ $200?[
try{ Ylf4q/-
Thread.sleep(nSecond); S&0x:VW
} =osj}(
catch(Exception e) {J]|mxo
{ O//e0?]W
e.printStackTrace (); #-`lLI:w0
} WZr~Pb9
} a"zoDD/
g$tW9 Q
//日志 BCj&z{5"7e
public static void log(String sMsg) ?b0\[
{ t>[r88v
System.err.println(sMsg); h Na<LZ
} wVVe L$28
v3NaX.
MoA{ /{
public static void log(int sMsg) g,;MV7yE
{ JB|I/\(A
System.err.println(sMsg); B?M+`;
} y/FisX
} )v9[/ ]*P
pA2U+Q@
j0GI[#
/* p#kC#{<nE
**TestMethod.java s5pY)6)
*/ P8jK yo
package NetFox; fin15k
w9FI*30
3%} Ma,
public class TestMethod { cm]]9z_<
gr;M
NR*SEbUU*
public TestMethod() L`#+ZLo
{ ///xx/weblogic60b2_win.exe kpdFb7>|
try{ ^WNJQg'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H07j&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |}`5<a!6U
SiteFileFetch fileFetch = new SiteFileFetch(bean); >W;i2%T
fileFetch.start(); I%p#E#[G
} qj1z>,\
catch(Exception e){e.printStackTrace ();} X=3@M_Jzo
#^9;<@M
cC4T3]4l'
} Zx_m?C_2_
coWBKWF
R+K[/AA
public static void main(String[] args) #RF=a7&F
{ Trrh`@R
new TestMethod(); gy{a+Wbc*
} <}%ir,8
} B /W$RcV
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