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)); c4z&HQd
} !73y(Y%TE
for(int i=0;i<nEndPos.length-1;i++) Pps$=`
{ N{J 1C6
nEndPos = nStartPos[i+1]; <rC%$tr
} gt{kjrTv&
nEndPos[nEndPos.length-1] = nFileLength; gL<n?FG4b
} -K|1w'E
} 9f~qD&~
T//xxH]w-
^h?fr`
//启动子线程 <4rnOQ:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "FHJ_$!
for(int i=0;i<nStartPos.length;i++) CR4O#f8\
{ >n7h%c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M CC4'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [>ghs_?dZ
nStartPos,nEndPos,i); 8}n<3_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pRQ7rT',v
fileSplitterFetch.start(); !*]i3 ,{7v
} 7hJX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7@@g|l]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?%3dgQB'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n)yDep]$G
nEndPos = " + nFileLength); UPtj@gtcY
// fileSplitterFetch[nPos.length-1].start(); @a9.s
21TR_0g&<
v_KO xV:<`
//等待子线程结束 LR=Ji7
//int count = 0; f*%kHfaXgN
//是否结束while循环 vyZ&%?{*R
boolean breakWhile = false; WK|5:V8E
]SJ#:7
T)P)B6q
while(!bStop) B*tYp
{ {aAd (~YZ
write_nPos(); @}y.
Utility.sleep(500); sVx}(J
breakWhile = true; gnJ8tuS
s{b\\$Rb
*RkUF!)(
for(int i=0;i<nStartPos.length;i++) ,HP }}K+S
{ .wNXvnWr
if(!fileSplitterFetch.bDownOver) :M(uP e=D
{ NP;W=A F
breakWhile = false; ?^VPO%
break; t:2DB)
} `D;*.zrA
} U:8[%a
if(breakWhile) }Xj25` x
break; mx^Ga=: ?
PC9,;T&7_
{+9RJmZg
//count++; I)mB]j
//if(count>4) &nIu^,.
// siteStop(); =}Tm8b0
} lpG%rN!
3(c-o0M
k[@P526
System.err.println("文件下载结束！"); T-N>w;P
} 7^><Vh"qV
catch(Exception e){e.printStackTrace ();} 2.3_FXSt
} F*P0=DD
f$dPDbZQ
sZrVANyqb
//获得文件长度 {KgA V
public long getFileSize() ^}+\52w
{ @` KYgjjH
int nFileLength = -1; AJ7w_'u=@
try{ N,TV?Q5l7
URL url = new URL(siteInfoBean.getSSiteURL()); @jn&Wf?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C6)YZC
httpConnection.setRequestProperty("User-Agent","NetFox"); M!,H0(@G
`#$}P;W
O|H:
int responseCode=httpConnection.getResponseCode(); L('1NN2
if(responseCode>=400) ZPZh6^cc
{ 0j@mzd2
processErrorCode(responseCode); E7$&:xqx
return -2; //-2 represent access is error iTHwH{!
} vK!`#W`X
*?<N3Rr*
rxyv+@~Nc
String sHeader; {VAih-y
* BM|luYL
!R8%C!=a
for(int i=1;;i++) m[}P
{ :{a< ~n`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qA[lL(
//Utility.log(in.readLine()); $0[T<]{/?
sHeader=httpConnection.getHeaderFieldKey(i); .\caRb[
if(sHeader!=null) OD)X7PU
{ ox&5}&\
if(sHeader.equals("Content-Length")) W'4/cO
{ ]q"&V\b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &ZD@-"@
break; jC&fnt,O
} !R@LC
} *duG/?>P
else +iC:/CJL
break; b/_Zw^DPC
} .,u>WIUxj
} RQE]=N
catch(IOException e){e.printStackTrace ();} Aits<0
catch(Exception e){e.printStackTrace ();} ^(JrOh'
^{"i eVn
hwGK),?"+
Utility.log(nFileLength); Ovt]3`U9J
EA~xxKq
e_b,{l#
return nFileLength; +Q+O$-a<
} o(ow{S@=4
xVPSL#>
4$R!)
//保存下载信息（文件指针位置） IRg2\Hq
private void write_nPos() =G}a%)?As\
{ 30HUY?'K
try{ Z8=?Hu
output = new DataOutputStream(new FileOutputStream(tmpFile)); M!6Fnj
output.writeInt(nStartPos.length); TFkG"ev
for(int i=0;i<nStartPos.length;i++) ^\v]Ltd
{ QD.5oS
// output.writeLong(nPos); 0se%|Z|8
output.writeLong(fileSplitterFetch.nStartPos); -o+t&m
output.writeLong(fileSplitterFetch.nEndPos); QjLU@?&
} uL)MbM]
output.close(); 3}}/,pGSc
} "\*)KH`C
catch(IOException e){e.printStackTrace ();} :Ak^M~6a5
catch(Exception e){e.printStackTrace ();} | +;ZC y
} %ZoJu
lH3.q4D 5
<l1/lm<#
//读取保存的下载信息（文件指针位置） Mg\588cI
private void read_nPos() k$v7@|Aw
{ c&T5C,]
try{ *wJ$U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W^elzN(
int nCount = input.readInt(); W\[E
nStartPos = new long[nCount]; '\{ OQH
nEndPos = new long[nCount]; MLr L"I"
for(int i=0;i<nStartPos.length;i++) ~"S5KroN
{ @Xoh@:j\
nStartPos = input.readLong(); AkW,Fp1e
nEndPos = input.readLong(); 5V<6_o
} ?4SYroXUX|
input.close(); eQQVfEvS
} 6No.2Oo
catch(IOException e){e.printStackTrace ();} TJNE2
catch(Exception e){e.printStackTrace ();} I&|8 qx#
} S*}GW-)oA
CH+%q+I
+]t9kr
private void processErrorCode(int nErrorCode) 0(&uH0x
{ T\wOGaCW
System.err.println("Error Code : " + nErrorCode); Z2{$FN
} 3Dc^lfn
*Iw19o-I
toF6 Z
//停止文件下载 %/zHL?RqJ
public void siteStop() ?Zv5iI
{ fx 08>r
bStop = true; RGV{KL
for(int i=0;i<nStartPos.length;i++) _BG`!3U+
fileSplitterFetch.splitterStop(); *QW.#y>"j
9^SrOW6~
w}}+8mk[
} j,,#B4b
} q&ed4{H<
//负责部分文件的抓取 RW>F %P
**FileSplitterFetch.java dd=5`Bo9Yh
*/ qyyLU@hd
package NetFox; s5 Fn("h]n
\i~5H]?d
IKp(KlA
import java.io.*; 7({.kD6
import java.net.*; 'H1"z!]
kH=~2rwm
K6<1&
public class FileSplitterFetch extends Thread { *|+ ~V/#
GmGq69]J*
I |D]NY^
String sURL; //File URL `).;W
long nStartPos; //File Snippet Start Position $AFiPH9
long nEndPos; //File Snippet End Position Z?",+|4
int nThreadID; //Thread's ID nDC5/xB
boolean bDownOver = false; //Downing is over HSl$ U0
boolean bStop = false; //Stop identical 7f=9(Zj
FileAccessI fileAccessI = null; //File Access interface .>zkS*oX4z
of<>M4/g4y
Dc>)js|"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;rta#pRn
{ cmh/a~vYaY
this.sURL = sURL; Y@%6*uTLa
this.nStartPos = nStart; ^_ZQf
this.nEndPos = nEnd; PzTTL=G +
nThreadID = id; VA'<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 fs]Zw mA^
} ]O&A:Us
=09j1:''<d
s.dn~|a
public void run() ?Ve5}N
{ !"J*
while(nStartPos < nEndPos && !bStop) qXW2a'~
{ TAJ9Y<
4_I,wG@
-+I! (?
try{ XWy iS\
URL url = new URL(sURL); \ZDT=?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GrQAho
httpConnection.setRequestProperty("User-Agent","NetFox"); A8eli=W
String sProperty = "bytes="+nStartPos+"-"; |-aj$u%~
httpConnection.setRequestProperty("RANGE",sProperty); \&qVr1|
Utility.log(sProperty); CX'E+
B 9Mwj:)}
J2[QHr&tn
InputStream input = httpConnection.getInputStream(); \T]"pE+8l
//logResponseHead(httpConnection); !V-SV`+X
R+JI?/H
b~1p.J4
byte[] b = new byte[1024]; K;xW/7?
int nRead; 'IW+"o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =L wX+c
{ n0i&P9@B1
nStartPos += fileAccessI.write(b,0,nRead); o%9>elOju
//if(nThreadID == 1) +@qk=]3a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EhUy7b,1_
} yaR;
J+|ohA
kL|Y-(FPo%
Utility.log("Thread " + nThreadID + " is over!"); 835Upj>
bDownOver = true; v_@_J!s
//nPos = fileAccessI.write (b,0,nRead); R39R$\
} t(rU6miN
catch(Exception e){e.printStackTrace ();} "=n8PNV/ c
} _TXV{<E6
} _~(Xd@c(
Y)*lw
l=]vC +mU
//打印回应的头信息 O]g+z$2o
public void logResponseHead(HttpURLConnection con) E$>e< T
{ zB$6e!fc
for(int i=1;;i++) D5m\u$~V
{ kZ.3\
String header=con.getHeaderFieldKey(i); `k|nf9_
if(header!=null) )x7hhEk=^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uRy6~'
Utility.log(header+" : "+con.getHeaderField(header)); 5#o,]tP
else =|%T E
break; RM+E
} feW9>f;
} PK4UdT
*a%PA(%6
7:<Ed"rdE
public void splitterStop() `x VA]GR4c
{ JrAc]=
bStop = true; *]6dV'
} {@$3bQ
UVJ(iNK"
0cUt"(]
} %p60pn[(
pb Ie)nK
ix+x-G
/* uP]o39b;V
**FileAccess.java z0[ZO1Fo(
*//文件访问(定位，写) |pR$' HO
package NetFox; 8Q -F
import java.io.*; l7!)#^`2_
)x&@j4,
NF!1)
public class FileAccessI implements Serializable{ ]:fCyIE
,P@-DDJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?\M6P?tpo&
RandomAccessFile oSavedFile; p'k+0=
long nPos; j]"xck
X2YOD2<v
3&fFIab9
public FileAccessI() throws IOException 9/(c cj
{ f {Z%:H
this("",0); _ng=5
} arKmc@"X
O f@#VZ
p30&JJ!~"
public FileAccessI(String sName,long nPos) throws IOException 8I0Tu
{ gCr|e}w-
oSavedFile = new RandomAccessFile(sName,"rw"); cCGXB|9fYR
this.nPos = nPos; f\U&M,L\'
oSavedFile.seek(nPos); 8Vhck-wF
} t`ceVS
xcvr D
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public synchronized int write(byte[] b,int nStart,int nLen) $YY)g$
{ _JTxm>
int n = -1; e)dWa'2<
try{ yPh2P5}H>
oSavedFile.write(b,nStart,nLen); vSC0D7BlG
n = nLen; bH&)rn
} 0/@ X!|X
catch(IOException e) T) tZU?
{ auTTvJ
e.printStackTrace (); kefv=n*]l
} !FO^:V<|5
qJXsf M6
N46$EsO!h
return n; fCf#zV[
} @U3foL2\
W({TC
A9l})_~i
} WCmNibj
B5,QJ W*
\btR^;_\A
/* Hn9F gul&
**SiteInfoBean.java Z\=04[
*/ =PFR{=F
package NetFox; SU%rWH
"4ozlWx
k/_8!^:'
public class SiteInfoBean { u2-@?yt
leES YSY:
CI!Eq&D,
private String sSiteURL; //Site's URL 2@3.xG
private String sFilePath; //Saved File's Path vf'cx:m
private String sFileName; //Saved File's Name -<51CDw,
private int nSplitter; //Count of Splited Downloading File )0U3w#,JQ
w~$c= JO#
Uc&6=5~Ys\
public SiteInfoBean() d]7|v r]
{//nSplitter的缺省值为5 Dpdn%8+Z
//default value of nSplitter is 5 hk@`N;dn
this("","","",5); LGo2^Xx
} \U!@OX.R'M
X$-boe?
S?Bc~y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?{"XrQw
{ P^8^1-b
sSiteURL= sURL; &gA6+b'
sFilePath = sPath; WjY{rM,K
sFileName = sName; rmPne8D=c(
this.nSplitter = nSpiltter; A-a17}fta
[arTx^
-v;n"Zy1
} ,G[r+4|h
vXyuEEe
C{UF~
public String getSSiteURL() ~JwpNJs
{ /`+Hwdk
return sSiteURL; W&+y(Z-t
} TsaW5ho<p
9Qzjqq:"Li
U#;51_
public void setSSiteURL(String value) NqJ<!q)
{ w0Fwd
sSiteURL = value; 01LZE,.
} r]k*7PK
~~C6)N~1
2Vp>"
public String getSFilePath() /[a|DUoHO
{ E tJ~dL)
return sFilePath; 45x,|h[F{5
} @J-plJ4e
8yE!7$Mj
5%<TF.;-J
public void setSFilePath(String value) >vlQ|/C
{ H<`^w)?
sFilePath = value; ?^LG hdR
} {UB%(E[Mr
~TYbP
;#3ekl{-g
public String getSFileName() .Qd}.EG
{ 89zuL18V
return sFileName; )fNGB]%
} ZV!R#Xv
RK?jtb=&A
/^w"' '
public void setSFileName(String value) \).Nag+
{ XjX 2[*l
sFileName = value; 5pO]vBT
} o g_Ri$x8
D899gGe
,# ]+HS^B
public int getNSplitter() T3=(`
{ ytEQ`
return nSplitter; MzcB3pi
} V {p*z
neF8V"-u&
aZ$/<|y~:_
public void setNSplitter(int nCount) >GgE,h
{ cI5N"U@yN
nSplitter = nCount; {Jrf/p9w
} 5`"iq "5Cf
} $Jcq7E~
@9aGz6k+
?fV?|ZGZI
/* +vf:z?I8
**Utility.java y>`5Kyj3-@
*/ J<rlz5':
package NetFox; yX`#s]M
Hoj8okP
975 _d_U
public class Utility { avg4K*vv
)Bo]=ZTJ^
guU=NQZ
public Utility() Yr=8!iR$
{ rS4%$p"
JRXRi*@
7{4w2)
} d.p'pGL
;`+`#h3-V
//线程睡眠 uxb:^d?D!
public static void sleep(int nSecond) >VP5vkv=
{ pl|h>4af
try{ yplG18
Thread.sleep(nSecond); W2hA-1
} 6lsEGe
catch(Exception e) afx'
{ z3W3=@
e.printStackTrace (); ?_%u)S*g
} J1X~vQAe
} NO2(vE
TdFT];:
//日志 pM9yOY
public static void log(String sMsg) >g]ON9CGH
{ P#MK
System.err.println(sMsg); O[FZq47
} i$C-)d]
RkA8
*C7F2o
public static void log(int sMsg) at| \FOKj
{ 1'Rmg\(
System.err.println(sMsg); Zj!Abji=O
} :^#vxdIC?
} s6n`?,vw
hF>u)%J/S
UV@0gdy[
/* `eR 7H>I
**TestMethod.java Gq1)1
*/ "}zt`3
package NetFox; ^_W40/c3
to>
VD[pZ2;4
public class TestMethod { )+EN$*H
p0VUh!
cU8xUpq
public TestMethod() Ee)xnY%(
{ ///xx/weblogic60b2_win.exe +qy6d7^
try{ }`_(<H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RB$ z]/=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p$XKlg&
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?JXa~.dA
fileFetch.start(); wxdyF&U n
} B(,:haAr
catch(Exception e){e.printStackTrace ();} !MV@) (.
!Z|($21W
i=rH7k
} H M:r0_
L'E^c,-x~
}r3~rG<D71
public static void main(String[] args) ,H[SI0];
{ q-_' W,
new TestMethod(); G5Ykbw#
} /XbW<dfl
} {/ 2E*|W~I
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