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)); C$PS@4'U
} 'UWkJ2:!
for(int i=0;i<nEndPos.length-1;i++) {9}CU~R
{ oC49c~`8
nEndPos = nStartPos[i+1]; -u'"l(n)~
} 2;WbXc!#!
nEndPos[nEndPos.length-1] = nFileLength; 8$A0q%n
} ls:oC},p*
} ^M6lF5
e9RYk:O
[V:~j1{3
//启动子线程 $8UW^#Bpq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kt)Et
for(int i=0;i<nStartPos.length;i++) +sjzT[ Dn
{ l;@+=uVDHm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6{]F#ig=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0>7Ij7\[8
nStartPos,nEndPos,i); ;J,(YNI 1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [UZr|F
fileSplitterFetch.start(); rf%lhBv
} Rh|9F yN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "%Y=+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c_*w<vJ-'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -'d:~:1f
nEndPos = " + nFileLength); yiC7)=
// fileSplitterFetch[nPos.length-1].start(); s. A}ydtt
EUuSN| a
>x;\H(g
//等待子线程结束 aF^NYe
//int count = 0; 94ruQ/
//是否结束while循环 Oa~ThbX7
boolean breakWhile = false; 2.niB>
,GYQ,9:
)^{}ov
while(!bStop) G]f|?
{ 8CZfz!2
write_nPos(); O;<wDh)Yt
Utility.sleep(500); M['O`^
breakWhile = true; 77O$^fG2
3PU_STSix
/"?DOsJ.
for(int i=0;i<nStartPos.length;i++) W<prY
{ 8(\}\4G_
if(!fileSplitterFetch.bDownOver) s<F*kLib
{ Zyz#xMmM
breakWhile = false; {+WY,%e
break; e6j1Fa9
} #Z2'Y[@.
} ?QT6q]|d0+
if(breakWhile) w/m@(EBK
break; '?veMX
w/nohZF6H
~h3G}EH
//count++; ?<!qF:r:
//if(count>4) W^L^7
// siteStop(); /_qq(,3
} r3g^0|)
Ia#!T"]@W6
FHr)xqo=~
System.err.println("文件下载结束！"); /o;L,mcx*
} W"vLCHTh
catch(Exception e){e.printStackTrace ();} tjx8UgSi
} hXjZ>n``
1 6zxPSTr}
Ie. on)
//获得文件长度 fasWb&~z
public long getFileSize() +112{v=!i
{ ]64}Xob87_
int nFileLength = -1; B~KxUp
try{ AuXUD9-
URL url = new URL(siteInfoBean.getSSiteURL()); z.cDbkf}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H1kI+YJ@
httpConnection.setRequestProperty("User-Agent","NetFox"); B&a{,.m&q6
FFcCoPX_
Z2$_9.
int responseCode=httpConnection.getResponseCode(); `;6M|5G
if(responseCode>=400) ?CQE6ch
{ H<_Tn$<zH.
processErrorCode(responseCode); /@ @F nQ++
return -2; //-2 represent access is error M co:eE
} vzg^tJ
Hloe7+5UD
^}-l["u`
String sHeader; cRnDAn#42
KNAvLcg
dRron_'
for(int i=1;;i++) Jj \nye+
{ Ea@0>_U|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _ Lh0
//Utility.log(in.readLine()); _C/|<Ot:
sHeader=httpConnection.getHeaderFieldKey(i); M?h{'$T
if(sHeader!=null) G7 UUx+X
{ ['}|#3*w
if(sHeader.equals("Content-Length")) ML12&E>
{ |KYl'"5\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kzZgNv#G;
break; o&1mX
} })-V,\
} HqWWWCWal
else Zmyq6.1q~
break; kS-BB[T
} I_ZJnu<
} w"9h_;'C_
catch(IOException e){e.printStackTrace ();} Z5q%L!4G
catch(Exception e){e.printStackTrace ();} ~JL qh
_VT{2`|})
b\}a
Utility.log(nFileLength); caQ1SV^{9
d%P2V>P
FSQB{9,H
return nFileLength; \|Af26
} .z,-ThTH@\
ElW\;C:K*
MeBTc&S<
//保存下载信息（文件指针位置） DS(>R!bb
private void write_nPos() mKe6rEUs|
{ =T[P
try{ daKZ*B|
output = new DataOutputStream(new FileOutputStream(tmpFile)); Bo"9;F
output.writeInt(nStartPos.length); 3%)cUkD
for(int i=0;i<nStartPos.length;i++) &s`)_P[
{ bPFGQlmIO
// output.writeLong(nPos); B9"o Ru^}
output.writeLong(fileSplitterFetch.nStartPos); HKJCiQ|k
output.writeLong(fileSplitterFetch.nEndPos); ejV`W7U
} YdCl
output.close(); (sKg*G2
} oYw?kxRZ
catch(IOException e){e.printStackTrace ();} R1LirZlzJ
catch(Exception e){e.printStackTrace ();} y ~ K8
} 0OHXg=
jo"nK,r
#!Cg$6%x9
//读取保存的下载信息（文件指针位置） 3~P$p<
private void read_nPos() SdlO]y9E
{ O<s7VHj
try{ .\a+m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |^8ND#x
int nCount = input.readInt(); 55O}SUs!P
nStartPos = new long[nCount]; VjWJx^ZL#
nEndPos = new long[nCount]; Hi[lN7ma8
for(int i=0;i<nStartPos.length;i++) q<E7qY+
{ c/K#W$ l
nStartPos = input.readLong(); HHx:s2G
nEndPos = input.readLong(); 6h/!,j0:t_
} ^ZsIQ4@`
input.close(); tQzbYzGb7
} @M\JzV4 A[
catch(IOException e){e.printStackTrace ();} !6|_`l>G,
catch(Exception e){e.printStackTrace ();} j4i$2ZT'
} K;"H$0!9
WDY\Fj
k H65k (
private void processErrorCode(int nErrorCode) )2).kL>
{ <o()14
System.err.println("Error Code : " + nErrorCode); _]*[TGap
} Mt4]\pMUb
#6@hVR.
0t!ZMH
//停止文件下载 .'M.yE~5J
public void siteStop() 5]*lH t
{ bq7+l4CGTv
bStop = true; mfZbo#KS#v
for(int i=0;i<nStartPos.length;i++) |iJz[%
fileSplitterFetch.splitterStop(); .K~V DUu
Q)aoc.f!v
:j+E]|d(~6
} <T7@,_T
} S<]k0bC
//负责部分文件的抓取 Ia](CN*;6
**FileSplitterFetch.java ek)rsxf1A
*/ TSFrv8L
package NetFox; BMAWjEr
lJAzG,f
`P\H{
import java.io.*; *P *.'XM
import java.net.*; :c]y/lQmV
~*EipxhstJ
a)2l9
public class FileSplitterFetch extends Thread { %u%;L+0Q[
ypM,i
6T4"m
String sURL; //File URL 9Y2u/|!.3
long nStartPos; //File Snippet Start Position ; ]%fFcy
long nEndPos; //File Snippet End Position }%w;@[@L
int nThreadID; //Thread's ID K_U`T;Z\
boolean bDownOver = false; //Downing is over bzpi7LKN
boolean bStop = false; //Stop identical $]?pAqU\
FileAccessI fileAccessI = null; //File Access interface 27gHgz}}
'*Y mYU
|8}y?kAC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0D4 4
{ N''xdz3Z
this.sURL = sURL; D`n<!"xg@$
this.nStartPos = nStart; rMG[,:V
this.nEndPos = nEnd; WClprSl8
nThreadID = id; dh]Hf,OLF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =KR^0<2r
} GX19GI@k
~C 3Y/}
q#Otp\f
public void run() q:up8-LAr
{ !pe[H*Cy
while(nStartPos < nEndPos && !bStop) VKXi*F9
{ 7202N?a {
LL:N/1ysG
J8FzQ2
try{ ,%m~OB#
URL url = new URL(sURL); f(}&8~&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); si%V63^lN
httpConnection.setRequestProperty("User-Agent","NetFox"); `&a8Wv
String sProperty = "bytes="+nStartPos+"-"; Q>yj<DR
httpConnection.setRequestProperty("RANGE",sProperty); iU0jv7}n
Utility.log(sProperty); dh}"uM}a
L9hL@
_j$V[=kdM/
InputStream input = httpConnection.getInputStream(); X%!?\3S
//logResponseHead(httpConnection); ?>=vKU5
lKQjG+YF
:1'1n
byte[] b = new byte[1024]; r_ 9"^Er
int nRead; zGO_S\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ( K-7z
{ P[`>*C\9c
nStartPos += fileAccessI.write(b,0,nRead); p^{yA"MQ
//if(nThreadID == 1) 8oHIXnK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E]{0lG`l
} ViOXmK"
oMn'{+(w
8f?o?c|
Utility.log("Thread " + nThreadID + " is over!"); T}p|_)&y
bDownOver = true; Rp zuSh
//nPos = fileAccessI.write (b,0,nRead); 6EWCJ%_
} HE4S%#bH>
catch(Exception e){e.printStackTrace ();} `T2DGv
} mV7_O//
} |[V6R\l39
wc6#C>=F
muK)Yw[#N
//打印回应的头信息 UWCm:eRQ
public void logResponseHead(HttpURLConnection con) *}r6V"pH~
{ 5U_ar
for(int i=1;;i++) `ER#S_}
{ kyB>]2
String header=con.getHeaderFieldKey(i); T/L\|_:'
if(header!=null) Odt<WG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]~m=b`o
Utility.log(header+" : "+con.getHeaderField(header)); m&*0<N
else UBwYwm0
break; BhyLcUBuB
} PwAmnk !
} a<pEVV\NB~
A[88IMZs
GO#eI]>/r
public void splitterStop() w `M/0.)V
{ ,;= S\
bStop = true; iQh:y:Jo1&
} p{V(! v|
sYTToanA$?
78mJ3/?rC
} FP6JfI8
Zg])uM]\2i
3v~}hV/RUy
/* )6he;+
**FileAccess.java w/0;N`YB
*//文件访问(定位，写) 9Xh<vh8&
package NetFox; ,(yaWd6
import java.io.*; n<[H!4
-fz(]d
,+_gx.H2j
public class FileAccessI implements Serializable{ J:;nN-\j
#b=*hi`E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 No/D"S#
RandomAccessFile oSavedFile; Zvz}Z8jW
long nPos; i\L7z)u
^\PNjj*C i
`? f sU
public FileAccessI() throws IOException TsRbIq[
{ R<>uCF0
this("",0); YH[HJ#:7r
} wlX K2D
`\-mqe
28,HZaXhc
public FileAccessI(String sName,long nPos) throws IOException 6;\Tps;A
{ hcD.-(-;)
oSavedFile = new RandomAccessFile(sName,"rw"); iEBxBsz_
this.nPos = nPos; fVBu?<=d
oSavedFile.seek(nPos); 6[1lK8o
} 0Szt^l7
Fo| rRI2
k:E+]5
public synchronized int write(byte[] b,int nStart,int nLen) Bk4|ik}
{ QtqE&j
int n = -1; B\7 80p<
try{ $5yH8JU
oSavedFile.write(b,nStart,nLen); ^t)alNGos
n = nLen; YcuHYf5
} k{C|{m
catch(IOException e) )0@&pEObm
{ w3oe.hWP3N
e.printStackTrace (); 9O#?r82
} Ru`7Xd.
oO,"B8a
w259':
return n; 1A9Gf
} $QuSmA<4lS
;ZLfb n3\
T`^LWc"
} IQ}YF]I;
F|W(_llfM
:j!N7c{
/* +QFY.>KH
**SiteInfoBean.java T_?,?
*/ c:z<8#A}
package NetFox; q0]Z` <w
]a=Bc~g91
!xZ`()D#
public class SiteInfoBean { e;)&Hc:Z
,n+~S^r
E@$HO_;&
private String sSiteURL; //Site's URL c`G~.paY|
private String sFilePath; //Saved File's Path V4 Wn
private String sFileName; //Saved File's Name |zSoA=7?
private int nSplitter; //Count of Splited Downloading File <DM:YWNa
i/WiSwh:
8Ow0A
public SiteInfoBean() GGwHz]1L
{//nSplitter的缺省值为5 be{tyV
//default value of nSplitter is 5 < {dV=
this("","","",5); naKB2y]l
} e$@azi1
t12 xPtN1
o.H(&ex|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) oT27BK26?h
{ p=U5qM.O
sSiteURL= sURL; :Qra9; Y
sFilePath = sPath; `]:&h'
sFileName = sName; Nl`8Kcv
this.nSplitter = nSpiltter; E; Z1HF R
['n;e:*
$3MYr5
} 4 U`5=BI
0?nm`9v6
,=kQJ|
public String getSSiteURL() Kzd)Z fnD0
{ Fs EPM"&?h
return sSiteURL; A `n:q;my
} gcfEJN4'
(t)a u
K2R[u#Q
public void setSSiteURL(String value) {n>W8sN<
{ pI|H9
sSiteURL = value; BWN[>H %S
} S7 Tem:/
(Q09$
FO5'<G-
public String getSFilePath() !EQMTF=(
{ v(tr:[V
return sFilePath; h .$3jNU
} C6C7*ks
"ewB4F[
q9&d24|
public void setSFilePath(String value) ^g56:j~?
{ 77ID 82
sFilePath = value; h0fbc;l
} GM<r{6Qy
&<sN(;%0R
Q@lJ|
public String getSFileName() 7 n=fB#!*3
{ ( nH3
return sFileName; U0:tE>3`
} 2x7%6'
mmj6YQ0a
ES#K'Lf
public void setSFileName(String value) }TCOm_Y/qL
{ E|Lv_4lb=
sFileName = value; `<L6Q2Y>j
} { +%S{=j
5'Fh_TXTD
{s=$.Kg
public int getNSplitter() JUlV$b.)J
{ g2<xr;<t^
return nSplitter; qeyBZ8BG
} HEjrat;5
m_z1|zM}o
? h$>7|
public void setNSplitter(int nCount) 7QlA/iKqK
{ 5!PU+9Kh
nSplitter = nCount; m{bw(+r
} q)uq?sZe
} @"m? #
C9q`x2
^vmyiF
/* o|nj2.
**Utility.java 5[|MO.CB$
*/ 8L?35[]e
package NetFox; ? 1g<] ?
R9->.eE
Z=Oo%lM6B
public class Utility { 2EOt.4cP
;TK:D=p4
av1*i3
public Utility() dfo{ B/+
{ {qm(Z+wcmb
b7/1]
Y24:D7Q
} >4.{|0%ut
^zv28Wq>
//线程睡眠 )h~MIpWR
public static void sleep(int nSecond) SZCFdb
{ L`ZH.fN
try{ W)F2X0D>
Thread.sleep(nSecond); Vl!Z|}z
} 7K`A2
catch(Exception e) L44-: 3
{ a<[@p
e.printStackTrace (); 1@H3!V4
} MdWT[
} 0j1I
FxC@KZG
//日志 _wg6}3
public static void log(String sMsg) LmLV2f
{ @>J4K#"
System.err.println(sMsg); AO9F.A<T5
} X.,1SYG[
L!-@dz
4b8!LzKS
public static void log(int sMsg) ,2)LH'Xx
{ EM*YN=So
System.err.println(sMsg); Ftm%@S?
} YXJjqH3
} ()vxTTa
v!ULErs
gJ>?<F;
/* O1@xF9<
**TestMethod.java X+{4,?04+
*/ cT8jG,+"}
package NetFox; =F ZvtcCa
N`/6 By
/r|^Dc Nx
public class TestMethod { 6tM CpSJ
zQ}:_
im_W0tGvF
public TestMethod() S >uzW #
{ ///xx/weblogic60b2_win.exe EpeTfD
try{ "j9,3yJT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JLRw`V,o7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); X LPO_tD
SiteFileFetch fileFetch = new SiteFileFetch(bean); "!gd)^<e
fileFetch.start(); L&lNpMT
} i7})VDsZ
catch(Exception e){e.printStackTrace ();} u(SdjLf:
\{n]&IjA
v\t$. _at
} LI?rz<H!D
o\8yYX
L^)&"6oSa
public static void main(String[] args) 7 #_{UJ%
{ x<"e} Oo
new TestMethod(); &@A(8(%
} dapQ5JT/
} {y'c*NS
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