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)); bc , p}
} 6_N(;6kx(
for(int i=0;i<nEndPos.length-1;i++) nQ|r"|g
{ ]kG(G%r|M
nEndPos = nStartPos[i+1]; 5k|9gICyd*
} sB69R:U;
nEndPos[nEndPos.length-1] = nFileLength; RpLE 02U
} 64:fs?H
} a<]B B$~
qY 4#V k
1:Si,d,wh
//启动子线程 4Jx"A\5*G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Zw wqSyuGf
for(int i=0;i<nStartPos.length;i++) u.rY#cS,-R
{ )E+'*e{cK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q]p(u\*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a1Qv@p^._b
nStartPos,nEndPos,i); 86 W0rS[5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A<;SnXm
fileSplitterFetch.start(); Z4IgBn(Z_}
} OT&k.!=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _#vrb;.+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -.{g}R%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3j3N!T9
nEndPos = " + nFileLength); =/\:>+p^.y
// fileSplitterFetch[nPos.length-1].start(); z2Z^~,i
^U]UqX`
A/`%/0e
//等待子线程结束 U!Ek'
//int count = 0; ;NRF=d>
//是否结束while循环 *-xU2
boolean breakWhile = false; |g*XK6
I[n^{8gz
MTUn3;c/
while(!bStop) |hr]>P1
{ jMpD+Mb
write_nPos(); DfKr[cqLM
Utility.sleep(500); yeHDa+}
breakWhile = true; |2KAo!PI
;V<fB/S.=+
uw2hMt (N
for(int i=0;i<nStartPos.length;i++) +k`!QM>e-
{ Bp@v,)8*
if(!fileSplitterFetch.bDownOver) c*@G_rb
{ MQ"xOcD*F
breakWhile = false; ZI=v.wa
break; rylzcN9RM$
} \G-KplKS
} x.q+uU$^
if(breakWhile) i'\T R|qd
break; -{ZWo:,r~q
)wNP( @$L
p}cw{
//count++; |DsnNk0c
//if(count>4) *BR^U$,e
// siteStop(); O?|gp<=d
} tPF.r
l'eyq}&
AA7C$;Z15~
System.err.println("文件下载结束！"); [Vma^B$7Vj
} z[;z>8|c
catch(Exception e){e.printStackTrace ();} bcYF\@};
} Ih"XV
mWvl38
)+6MK(<"
//获得文件长度 =&:Y6XP
public long getFileSize() k`N^Vdr
{ \o^2y.q:>
int nFileLength = -1; q*9!,!e
try{ T~='5iy|
URL url = new URL(siteInfoBean.getSSiteURL()); 5^x1cUB]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8Q'0h m?
httpConnection.setRequestProperty("User-Agent","NetFox"); :*KHx|Q
_D+J!f^
[D4Es
int responseCode=httpConnection.getResponseCode(); c3CWRi`LE
if(responseCode>=400) |/)${*a4n
{ c.e2M/
processErrorCode(responseCode); >o=-$gz`
return -2; //-2 represent access is error XD2v*l|Po
} 3(,?S$>
Nb'''W-iu
|mw.qI|
String sHeader; N <Xq]! K-
XY3v_5~/1F
Xx>X5Fy
for(int i=1;;i++) #^A*
{ ?BZPwGMs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SR|`!
//Utility.log(in.readLine()); '?p<lu^^B
sHeader=httpConnection.getHeaderFieldKey(i); oc>{?.^
if(sHeader!=null) [UWdW
{ ElW~48
if(sHeader.equals("Content-Length")) VL` z[|e @
{ y1+*6|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '$ t
break; IvtJ0
} EZ`te0[
} %2{%Obp'
else c2'Lfgx4
break; x#xFh0CA
} ^<a t'jk6
} FWG6uKv
catch(IOException e){e.printStackTrace ();} [`"ZjkR_J
catch(Exception e){e.printStackTrace ();} a C\MJ9
b((M)Gz
ijK"^4i
Utility.log(nFileLength); !C3MFm{B
#(N+(():
&-Gqdnc
return nFileLength; VyXhl;
} 'mFqEn
L(|N[#
Q/(K$6]j
//保存下载信息（文件指针位置） IID-k
private void write_nPos() ~5%W:qwQ
{ ;RC{<wBTx
try{ 2a`o &S
output = new DataOutputStream(new FileOutputStream(tmpFile)); [6%VRqY
output.writeInt(nStartPos.length); 0zlb0[
for(int i=0;i<nStartPos.length;i++) :OhHb#D
{ @hiCI.?X
// output.writeLong(nPos); 4C61GB?Vy
output.writeLong(fileSplitterFetch.nStartPos); j7$e28|_n
output.writeLong(fileSplitterFetch.nEndPos); /v1Q4mq
} 75f"'nJ)
output.close(); m.# VYN`+A
} P2BWuhF
catch(IOException e){e.printStackTrace ();} Dwr)0nk
catch(Exception e){e.printStackTrace ();} %et }A93
} (|:M&Cna]
-:Da&V
|ef7bKU8
//读取保存的下载信息（文件指针位置） f_jo+z{-ik
private void read_nPos() ([T>.s
{ `scR*]f1+
try{ Z_};|B}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]@j*/IP
int nCount = input.readInt(); r3&G)g=u
nStartPos = new long[nCount]; S;3R S;
nEndPos = new long[nCount]; 8_BV:o9kL
for(int i=0;i<nStartPos.length;i++) qT{U(
{ `#F{Waww'
nStartPos = input.readLong(); v5!d$Vctu
nEndPos = input.readLong(); ]HKQDc'
} Z&Pg"a?\
input.close(); z1PBMSG
} `5cKA;j>b
catch(IOException e){e.printStackTrace ();} Cc+t}"^
catch(Exception e){e.printStackTrace ();} s@&`f{
} V)Z}En["1
j"ThEx0
0bceI
private void processErrorCode(int nErrorCode) FcR=v0),
{ NPhhD&W_
System.err.println("Error Code : " + nErrorCode); 8p^bD}lN7
} YIn',]p:
jqWu
wa<MRt W=
//停止文件下载 W]"zctE
public void siteStop() ^=BTz9QM
{ !o5 W
bStop = true; 5L+>ewl
for(int i=0;i<nStartPos.length;i++) =e/9&993
fileSplitterFetch.splitterStop(); j`JMeCG=Ee
Pu7_ v
Ye"o6_U"
} ,0~^>K
} ?Nup1!D
//负责部分文件的抓取 )JDs\fUE
**FileSplitterFetch.java ,V,`Jf
*/ Ff$L|
package NetFox; ?x$"+,
j-4VB_N@
=}lh_
import java.io.*; lW+\j3?Z$
import java.net.*; m;H.#^b*
_BM" ]t*
]9YJ,d@J
public class FileSplitterFetch extends Thread { Qiua
(X $=Q6
bV(Y`g
String sURL; //File URL ebm])~ZL
long nStartPos; //File Snippet Start Position T_s_p
long nEndPos; //File Snippet End Position 3/aMJR:o
int nThreadID; //Thread's ID ?+_Gs;DGVE
boolean bDownOver = false; //Downing is over dU6ou'pf
boolean bStop = false; //Stop identical "oTHq]Ku
FileAccessI fileAccessI = null; //File Access interface r;B8i!gD
98j>1"8
`e(c^z#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sR(9IW-
{ c2h{6;bfY
this.sURL = sURL; w:%o?pKet1
this.nStartPos = nStart; O;z,qo X
this.nEndPos = nEnd; o}$XH,-9&
nThreadID = id; W}--p fG
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JI?rL
} ~c8?>oN(
sc|_Q/`\.
^$%S &W
public void run() *'OxAfa#x
{ u6M.'
while(nStartPos < nEndPos && !bStop) c]$i\i#
{ AjmVc])
U1@IX4^2`
m#8m] Y
try{ d_AK`wR
URL url = new URL(sURL); 03xa'Of>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >NqYyW,%
httpConnection.setRequestProperty("User-Agent","NetFox"); dA-2%uJ
String sProperty = "bytes="+nStartPos+"-"; uXI_M)
httpConnection.setRequestProperty("RANGE",sProperty); 8;z6=.4xtg
Utility.log(sProperty); YCdS!&^UN
;lq;X{/
&Flglj~7l
InputStream input = httpConnection.getInputStream(); j;%-fvd;
//logResponseHead(httpConnection); I'\kFjc
@xQgY*f#
T#M,~lD
byte[] b = new byte[1024]; l=]cy-H
int nRead; So{x]x:f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y]2qd35u_A
{ flk=>h|
nStartPos += fileAccessI.write(b,0,nRead); WxW7qt
//if(nThreadID == 1) bIGHGd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A&s:\3*Kh
} s<*XNNE7
ykv94i?Q
`o<' x.I
Utility.log("Thread " + nThreadID + " is over!"); >QA uEM
bDownOver = true; z|=}1;(.
//nPos = fileAccessI.write (b,0,nRead); :Mb%A
} H:!7:
catch(Exception e){e.printStackTrace ();} HuB<k3#sPy
} z)'Mk[
} #rxVd 7f
RD\
NxjB/N
//打印回应的头信息 8*8Zc/{
public void logResponseHead(HttpURLConnection con) %TX@I$Ba
{ 5:O-tgig.
for(int i=1;;i++) =jlt5 z
{ ]x\-$~E
String header=con.getHeaderFieldKey(i); ${+ @gJ+S
if(header!=null) f-}[_Y%;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !xP8#|1
Utility.log(header+" : "+con.getHeaderField(header)); a-l;vDs
else [`p=(/I&L
break; |3F02
} XD|E=s
} mu?Eco`~
7s"< 'cx_F
XpmS{nb
public void splitterStop() >wb'QzF:
{ .{44a$)
bStop = true; %FXfqF9
} + ` s@
Q@ 2i~Qo[
F_Y7@Ei/
} =0^Ruh
QA2borfy
M7+nW ; e%
/* :>D[n1v
**FileAccess.java qtiz a~u
*//文件访问(定位，写) RQ'exc2x0
package NetFox; Swp;HW7x
import java.io.*; fQL"O}Z
YhOlxON
G2t;DN(
public class FileAccessI implements Serializable{ 5WC+guK7
SG-'R1 J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?shIj;c[
RandomAccessFile oSavedFile; vk*=4}:
long nPos; ,Y|^^?'j Q
.q[SI$qO/
'd+NVj{C
public FileAccessI() throws IOException tjGd )
{ )Psb>'X
this("",0); {Zh>mHW3
} )K,F]fc+O
#<e\QE'!
%=?cZfFqO
public FileAccessI(String sName,long nPos) throws IOException oI}kH=<,
{ -8r
oSavedFile = new RandomAccessFile(sName,"rw"); slg ]#Dy
this.nPos = nPos; ]wKzE4Z/
oSavedFile.seek(nPos); ]%BWIqbr
} Z^]|o<.<I
aYuD>rD
OiE;B
public synchronized int write(byte[] b,int nStart,int nLen) nBHnkbKoy
{ ,y+$cM(
int n = -1; GN!qyT
try{ O!Oumw,$
oSavedFile.write(b,nStart,nLen); :>TEDy~O%
n = nLen; 2RN)<\P
} FXzFHU/dP
catch(IOException e) tID%}Zv
{ AJSx%?h:6
e.printStackTrace (); X66VU
} x.3J[=z=>
i&vaeP25)
ynw5-aS3
return n; X=Ys<TM,
} p=C%Hmd5E
/[6j)HIS
es>W$QKlo
} [Z~ 2
nPs7c %
UK1_0tp]x
/* !'j?.F$}
**SiteInfoBean.java +,yK;^b
*/ !2z?YZhu
package NetFox; ?gPKcjgoH!
^)?d6nI
M/q E2L[y
public class SiteInfoBean { CBDG./
rQEyD
NM0tp )h
private String sSiteURL; //Site's URL aB]m*~
private String sFilePath; //Saved File's Path !^v5-xO?rP
private String sFileName; //Saved File's Name {q<03d~9|G
private int nSplitter; //Count of Splited Downloading File -AhwI
_=q! BW
*dvDap|8W
public SiteInfoBean() xB@|LtdO9;
{//nSplitter的缺省值为5 Up:<=Kgci
//default value of nSplitter is 5 E;d7ch
this("","","",5); *loOiM\5a
} S.Z9$k%
v^ /Q 8Q
`Pw*_2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #-8\JEn
{ Qfky_5R\
sSiteURL= sURL; $2<d<Um~z
sFilePath = sPath; 'S2bp4G
sFileName = sName; u7xDau(c
this.nSplitter = nSpiltter; 0W3i()
sP-^~ pp
XxDaz1
} RZe'Kw -
2o#,kGd
|A%<Z(
public String getSSiteURL() nuoPg3Nl
{ bsd99-_(4
return sSiteURL; UxD5eJJ
} q %0Cg=
n!6Z]\8~$
T~fmk f$
public void setSSiteURL(String value) $7QoMV8V
{ H'MJ{r0,
sSiteURL = value; N$xtHtz8"
} __[xD\ES
zZiJ 9 e
Qu<Bu)`
public String getSFilePath() ~Ph\Sbp
{ 3+J0!FVla
return sFilePath; w'X]M#Q><
} 4t/&.
|!q$_at
F`nb21{0y&
public void setSFilePath(String value) 7O`o ovW$
{ BZb]SoAL
sFilePath = value; f'q 28lVf
} Xnuzr"4u
y fSM
B/Gd(S`@q
public String getSFileName() "4H8A=
{ g(O;{Q_
return sFileName; M=xQ=j?
} ;NV'W]
4yaxl\2
55t\Bms{
public void setSFileName(String value) `]$?uQ
{ sA9&/p/
sFileName = value; 7n)&FXK`
} fqs]<qi
W9t"aZor
~#}Dx :HH
public int getNSplitter() Ufo>|A6;$
{ qQ7w&9r.M
return nSplitter; U,1AfzlF
} NYABmI/0c
b'ml=a#i0
f>$h@/-*
public void setNSplitter(int nCount) kllQca|$4
{ RA a[t :|
nSplitter = nCount; 7:h!Wj-a]
} $R8w+ Id
} r^HAaGpC
j1Yq5`ia
vMSW$Bx ;
/* e=/&(Y
**Utility.java AF4?IH
*/ ,6<"
package NetFox; (#(Or
ID};<[
TTI81:fku
public class Utility { <64HveJ
% U`xu.
qH%")7>
public Utility() NWmtwS+@
{ V7=SV:+1or
E@QA".
}4%/pOi:f
} OCyG_DLT$5
H!IDV}dn
//线程睡眠 Mxz,wfaH>
public static void sleep(int nSecond) H*e'Cs/
{ "Q+83adY4x
try{ z>vtEV))
Thread.sleep(nSecond); ~waNPjPRG
} O ++/ry%k
catch(Exception e) >kYp%r6
{ 0.(<'!"y
e.printStackTrace (); x%BF{Sw
} b#Kq[}
} =_=*OEgO]
:.IN?X
//日志 A! 6r/
public static void log(String sMsg) mVH,HqsXa
{ !G=>ve
System.err.println(sMsg); cqL(^R.
} LPE)
SN]LeXesS
NCt~9xS.
public static void log(int sMsg) z:G}>fk5
{ yqcM(,0]
System.err.println(sMsg); ,ECAan/@
} Y)p4]>lT+8
} -}<g-*m"q
^Vo"fI`=C
f$D@*33ft
/* 5:gj&jt;)7
**TestMethod.java ( tn< VK.
*/ pC^[[5A
package NetFox; r,'O).7
eqFvrESN~=
o~~9!\
public class TestMethod { YOw?'+8
{e9Y !oFg
@l>Xnqx)
public TestMethod() BlaJl[Piv
{ ///xx/weblogic60b2_win.exe )Qr6/c8}
try{ e[4V%h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >h7$v~nra
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VK4/82@5
SiteFileFetch fileFetch = new SiteFileFetch(bean); bF6gBM@*
fileFetch.start(); dQ6GhS~
} uC[d%v`
catch(Exception e){e.printStackTrace ();} ;Q90Y&{L=$
,>S+-L8
ak2dn]]D
} *<dHqK`?C
,9vJtP+T+!
9HKf^+';n
public static void main(String[] args) pzSqbgfrQ
{ ?#ihJt,
new TestMethod(); ?pKN'`
} {rfte'4;=
} 'a_s%{BJXg
点击下载更多相关资料