http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); do8[wej<:
} /r7xA}se^
for(int i=0;i<nEndPos.length-1;i++) ?}Zo~]7E
{ 89M'klZ
nEndPos = nStartPos[i+1]; =`+D/ W\[Y
} yr%[IX]R
nEndPos[nEndPos.length-1] = nFileLength; .)/."V
} m7k }k)
} dXTD8 )&
fw&*;az
lAnq2j|
//启动子线程 V*n$$-5 1-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wNmpUO ?
for(int i=0;i<nStartPos.length;i++) ]gBnzh.
{ Ek<Qz5)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h3`}{ w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *O[/KR%
nStartPos,nEndPos,i); B?BOAH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UNDl&C2vz
fileSplitterFetch.start(); p$,G`'l
} }#s{."
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rw'}>?k]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8&EJ.CQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZLzc\>QX
nEndPos = " + nFileLength); [63\2{_^v
// fileSplitterFetch[nPos.length-1].start(); 4. R(`#f
,&BNN]k
+2iD9X{$MX
//等待子线程结束 1{N+B#*<[X
//int count = 0; .2%t3ul[
//是否结束while循环 =AO (
boolean breakWhile = false; O|t>.<T?
IR${a)
aL:|Dr3SX
while(!bStop) D?dBm
{ !H\;X`W|~D
write_nPos(); 1 iox0
Utility.sleep(500); 3@":&
breakWhile = true; M-t9M~
,P9F*;Dj
lrJV"H
for(int i=0;i<nStartPos.length;i++) Pm%xX~H
{ /0\g!29l<
if(!fileSplitterFetch.bDownOver) ~u%$ 9IhM
{ 3zB'AG3b
breakWhile = false; WVR/0l&bU
break; ~HIj+kN
} [7}3k?42X
} {dxFd-K3
if(breakWhile) tMw65Xei6b
break; U5C]zswL
9D14/9*(dU
~Eg]Auk7
//count++; E_~e/y"-
//if(count>4) CT'4.
// siteStop(); XYvj3+
} anSZWQ
__b4dv
$1ovT8
System.err.println("文件下载结束！"); Md4Q.8
} ?EC\.{
catch(Exception e){e.printStackTrace ();} ;~0q23{+;U
} (9`dLw5
deAV:c
}W^@mi
//获得文件长度 C`r:jA<LC,
public long getFileSize() LM eI[Ji
{ ^mLX}E]
int nFileLength = -1; rCF=m]1zxT
try{ g)6>=Qo`8E
URL url = new URL(siteInfoBean.getSSiteURL()); (2eS:1+'8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z7bJ<TpZ
httpConnection.setRequestProperty("User-Agent","NetFox"); ZP~H!
ZV--d'YiEm
sgOau\E
int responseCode=httpConnection.getResponseCode(); E#_/#J]UQn
if(responseCode>=400) no8\Oees
{ "_&ZRcd*
processErrorCode(responseCode); Y$>NsgQn6
return -2; //-2 represent access is error <-.@,HQ+
} sl-wNIQ
_]@u)$
$,K@xq5
String sHeader; rG?5z"
q;#AlquY@
;SE*En
for(int i=1;;i++) GZi`jp
{ gM&O dT+i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <n,QSy#
//Utility.log(in.readLine()); IoLP*D
sHeader=httpConnection.getHeaderFieldKey(i); *f 7rLM*
if(sHeader!=null) 5Xr})%L
{ .#~!w!T
if(sHeader.equals("Content-Length")) 8XYxyOl
{ "*HM8\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :|9vMM^$
break; ;"cQ)=s9Y
} SZTn=\
} p0W<K
else v' t'{g%
break; ;.AMP$o`(Y
} 8Ygf@*9L4
} 6:wk=#w
catch(IOException e){e.printStackTrace ();} j_5&w Znq
catch(Exception e){e.printStackTrace ();} L*4"D4V
Gx$m"Jeq\
3ibQbk
Utility.log(nFileLength); j*>Df2z
]*P9=!x|M
gHc1_G]
return nFileLength; ;:Z5Ft m
} iT:i '\~
~D@YLW1z(
tf6-DmMH
//保存下载信息（文件指针位置） 6am6'_{
private void write_nPos() wlP3 XF?
{ o@N[O^Q V
try{ _`p-^I
output = new DataOutputStream(new FileOutputStream(tmpFile)); C[.Xi
output.writeInt(nStartPos.length); C-A? mIC
for(int i=0;i<nStartPos.length;i++) W0MgY%Qv[
{ lv?`+tU2_
// output.writeLong(nPos); @?e~l:g})g
output.writeLong(fileSplitterFetch.nStartPos); y0Gblza
output.writeLong(fileSplitterFetch.nEndPos); c$,1j%[)
} p@O Ip
output.close(); omg#[
} 4 .c1
catch(IOException e){e.printStackTrace ();} QOK,-
catch(Exception e){e.printStackTrace ();} >yKz8SV#
} QGI@5
%0 {_b68x
;%d<Uk?
//读取保存的下载信息（文件指针位置） U]}FA2
private void read_nPos() eH7x>[lH.
{ KDb j C'3
try{ "Y^j=?1k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Zoxblk
int nCount = input.readInt(); .`~?w+ ~
nStartPos = new long[nCount]; r+m.!+
nEndPos = new long[nCount]; {St-
for(int i=0;i<nStartPos.length;i++) YvN]7tcb
{ 'k]~Q{K$
nStartPos = input.readLong(); eYP^.U)
nEndPos = input.readLong(); }F0<8L6%
} =r/8~~=
input.close(); ,,G"EF0A
} ?\8
catch(IOException e){e.printStackTrace ();} I5E=Ujc_
catch(Exception e){e.printStackTrace ();} 4Cu\|"5)
} $b2~Wj*-nJ
]e),#_M
"p3<-06
private void processErrorCode(int nErrorCode) 1OExa<Zq
{ g_{N^wS
System.err.println("Error Code : " + nErrorCode); 6)0.q|Q
} ;v\s7y
n%29WF6Zf
)V~=B]
//停止文件下载 4v/MZ:%C`
public void siteStop() l!XCYg@67
{ L3HC-
bStop = true; y+k^CT/u
for(int i=0;i<nStartPos.length;i++) P<Bx1H-z-
fileSplitterFetch.splitterStop(); O>+=cg
UFT JobU
fQC{LcS
} awo'#Y2>
} *<S>PbqLw
//负责部分文件的抓取 , @UOj=
**FileSplitterFetch.java +kd1q
*/ I;"pPJ3G
package NetFox; Nc(CGl:
mST8+R@S
Lhp&RGy
import java.io.*; UH6 7<_mK
import java.net.*; ?2#'>B
y>w;'QR&a
&~+QPnI>Pm
public class FileSplitterFetch extends Thread { VO eVS&}
n"RV!{&
;PC!
String sURL; //File URL "P#1=
long nStartPos; //File Snippet Start Position Dfzj/spFV
long nEndPos; //File Snippet End Position J)n_u),
int nThreadID; //Thread's ID r@C~_LgL)
boolean bDownOver = false; //Downing is over Dq~;h \='
boolean bStop = false; //Stop identical v[|W\y@H/3
FileAccessI fileAccessI = null; //File Access interface =q]!"yU[d
I ?Dp*u*
o$</At
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jr0j0$BF
{ d2Q*1Q@u
this.sURL = sURL; 8cOft ;|qB
this.nStartPos = nStart; 4j=K3m
this.nEndPos = nEnd; JqMF9|{H
nThreadID = id; 6Jq[]l"v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,k~' S~w.
} N8pL2y:R[P
uU3A,-{-
G`n $A/9Q
public void run() CR'%=N04^
{ T4wk$R L
while(nStartPos < nEndPos && !bStop) 131(0nl)=I
{ ?[Y(JO#
R`c[?U
@~$"&B
try{ [s[ZOi!;I
URL url = new URL(sURL); $4xSI"+M%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l~;>KjZg
httpConnection.setRequestProperty("User-Agent","NetFox"); 1b1Ab zN
String sProperty = "bytes="+nStartPos+"-"; xA(z/%
httpConnection.setRequestProperty("RANGE",sProperty); gm)Uyr$
Utility.log(sProperty); !5lV#w!vb
\fTQNF
ISNL='%
InputStream input = httpConnection.getInputStream(); %\<b{x# G
//logResponseHead(httpConnection); h*l$!nEN
SdYf^@%}F
=${.*,o
byte[] b = new byte[1024]; Qh&Qsyo%
int nRead; _|GbU1Hz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [-$ Do
{ WuUwd#e
nStartPos += fileAccessI.write(b,0,nRead); uRko[W(
//if(nThreadID == 1) 1`7zYW&L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "QdK Md
} To>,8E+GAb
nte?a e
K#Ck,Y"
Utility.log("Thread " + nThreadID + " is over!"); lcZ.}
bDownOver = true; DO80HS3ZD
//nPos = fileAccessI.write (b,0,nRead); Ll|_Wd.K,
} `?Q p>t
catch(Exception e){e.printStackTrace ();} (|^m9v0:
} b&F9<XLqq
} CfU|]<
0mSP
.fl r
//打印回应的头信息 uTR^K=Ve
public void logResponseHead(HttpURLConnection con) QnVr)4"
{ l@B9}Icq
for(int i=1;;i++) V,_m>$Mo
{ )6)bI.BY
String header=con.getHeaderFieldKey(i); pjFO0h_Y
if(header!=null) {3`385
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4=tR_s
Utility.log(header+" : "+con.getHeaderField(header)); 'vBZh1`p
else $].htm
break; D|9+:Y
} *(Dmd$|0|
} u)0I$Tc"
_h!.gZB3
7l69SQo]?
public void splitterStop() 3{3@>8{w
{ gY~r{
bStop = true; GjhTF|
} !CYC7HeF
0MHiW=
Ax=HDW}
} >lRZvf-i
G7CeWfS
ls@]%pz.1d
/* R p&J!hlA
**FileAccess.java U7s$';y"%
*//文件访问(定位，写) O{X~,Em=q
package NetFox; W r/-{Wt
import java.io.*; lv 8EfN
_HUbE /
P'Rw/co
public class FileAccessI implements Serializable{ NGc~%0n
Z[. M>|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o&q>[c
RandomAccessFile oSavedFile; E]`7_dG+T
long nPos; }sXTZX
+x"uP
FRd"F$U
public FileAccessI() throws IOException ^AP8T8v
{ X.t4;
this("",0); Z4VFfGCTL
} @V*dF|# /
q\6(_U#Tl
D`LBv,n
public FileAccessI(String sName,long nPos) throws IOException B3#G
{ !K>iSF<
oSavedFile = new RandomAccessFile(sName,"rw"); KMRPleF
this.nPos = nPos; IO+]^nY`
oSavedFile.seek(nPos); qNEp3WY:
} "bo0O7InOV
o:@Q1+p
Urr%SIakvM
public synchronized int write(byte[] b,int nStart,int nLen) PE%$g\#?
{ 1)(>'pY
int n = -1; -* ,CMw
try{ $O%{l.-O
oSavedFile.write(b,nStart,nLen); nYyhQX~]B
n = nLen; @RoZd?
} ^LMgOA(7
catch(IOException e) /5ZX6YkeH
{ USBQEt
e.printStackTrace (); TLdlPBnr8
} 1^\w7Rew2
q\Y4vWg
C%XO|sP
return n; /v R>.'
} ZL!u$)(V
c$g@3gL
t2N W$ -E
} &3Zq1o
js_`L#t
3'4+3Xo
/* @tH9$J*Y<
**SiteInfoBean.java =hPXLCeC
*/ 0xB2
package NetFox; Qz~uD'Rs/
h|qJ{tUWc$
vQMBJ&
public class SiteInfoBean { 8`q7Yss6F
TekUY m!G
|mb2<!ag{
private String sSiteURL; //Site's URL 7j]v_2S`
private String sFilePath; //Saved File's Path ~e{ @5.g
private String sFileName; //Saved File's Name 1 R5pf
private int nSplitter; //Count of Splited Downloading File ZwmucY%3
-#|D>
qA)OkR'm
public SiteInfoBean() Mbi]EZ
{//nSplitter的缺省值为5 *T5;dh (
//default value of nSplitter is 5 P$)g=/td1
this("","","",5); }s}g}t8v-
} <)VgGjZ-H
f`9Mcli!
V ;T :Q%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A6&*VD
{ d#ir=+o{h
sSiteURL= sURL; !J`lA
sFilePath = sPath; ZaFt4#
sFileName = sName; yayhL DL
this.nSplitter = nSpiltter; OK[J h
{K,In)4
4-(kk0]`z
} ;P@]7vkff
b9.M'P\
5~*)3z^V
public String getSSiteURL() pCIzpEsRs
{ %$!3Pbui
return sSiteURL; ag=d6q
} t'qYM5
>yBqi^aL
9j,g&G.K
public void setSSiteURL(String value) n>M`wF>
{ .w2ID
sSiteURL = value; .Mt3ec<
} TktH28tK
R@vcS=m7
kBu{ bxL
public String getSFilePath() oaoTd$/5
{ /R)wM#&
return sFilePath; >[}oH2oi
} hx;f/EPx
OrY[
^Co-!jM
public void setSFilePath(String value) Zi!Ta"}8
{ r* *zjv>
sFilePath = value; M^FY6TT4O
} c`;\sW-_W
"W|A^@r}
Uzu6>yT
public String getSFileName() [M?2axOC
{ sibYJKOy
return sFileName; ]-fkmnmWX
} %,$n^{v
?^}30V:E
dAo;y.3
public void setSFileName(String value) Rj8%% G-pt
{ P]_d;\ !"v
sFileName = value; 2eT?qCxqc
} dUI5,3*
'D\Q$q
)Fw/Cu
public int getNSplitter() _X6'uJ
{ &p0e)o~Ux
return nSplitter; &d#R'Z
} 8.E"[QktZ
gYpMwC{*d
Ui{%q@
public void setNSplitter(int nCount) v3tJtb^'!
{ bOS)vt*V
nSplitter = nCount; MK$u}G
} 'M90Yia
} sp9gz~Kq
J=4>zQLW
PNU(;&2<
/* Q?{%c[s
**Utility.java XYE|=Tr]
*/ x0*{oP
package NetFox; M`xiC
gv#\}/->4
Y+gY"
public class Utility { _T=g?0 q
VFHd2Ea(
LF<&gC
public Utility() ,Kit@`P%
{ 8`Ya7c>
eim+oms
my=f}%k=
} RaZ>.5 D
92+8zX
//线程睡眠 c\bL_
public static void sleep(int nSecond) {pzj@b 1S
{ 0c_xPBbB+
try{ I`>U#x*
Thread.sleep(nSecond); v9$!v^U"D
} rr<E#w
catch(Exception e) >ZA=9v
{ bp1AN9~
e.printStackTrace (); .8hI ad
} 2hE(h
} xNP_>Qa~
Uv^\[
//日志 6Rd4waj_,U
public static void log(String sMsg) &y[NCAeA
{ K%(y<%Xp
System.err.println(sMsg); 5~Y`ikwxL
} "L~(%Nx3
6|TSH$w_
O 4 !$
public static void log(int sMsg) E+td~&x
{ hbjAxioA
System.err.println(sMsg); l,ENMKA^D
} sdu?#O+c1
} }`"`VLh
1^iBS
8HF^^Cva
/* xU *:a[g
**TestMethod.java !-gU~0
*/ ,Q`qnn&
package NetFox; %+7]/_JO&
@KG0QHyiU
0p.bmQSH
public class TestMethod { g(7-3q8eq
"4j~2{{F
@@EI=\
public TestMethod() gcLz}84
{ ///xx/weblogic60b2_win.exe 4s\spvJ
try{ yDWIflP0;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R1jl<=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {]vD@)k
SiteFileFetch fileFetch = new SiteFileFetch(bean); >1y6DC
fileFetch.start(); ?ukw6T
} ?Ua,ba*
catch(Exception e){e.printStackTrace ();} Tc2.ciU
VYyija:
W,q @ww u
} nHK(3Z4G
pO]gf$
5dBftTv?
public static void main(String[] args) T U%@_vYR
{ 4aayMS!#
new TestMethod(); :_{8amO
} UD I{4+z
} n:j'0WW
点击下载更多相关资料