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)); wc,y+C#V
} In;z\"NN4
for(int i=0;i<nEndPos.length-1;i++) uN\9cQ
{ H*\ }W
nEndPos = nStartPos[i+1]; &&<^wtznO
} t=e0z^2i+
nEndPos[nEndPos.length-1] = nFileLength; 2iG(v._x
} D@JHi'F
} -owfuS?i=
#i]@"R
Xs`:XATb/
//启动子线程 ev guw*u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yauP j&^R
for(int i=0;i<nStartPos.length;i++) &'](T9kg=
{ Nm081ic2<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gaCGU<L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ckP3[@Su {
nStartPos,nEndPos,i); .$OInh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1)PR]s:-m@
fileSplitterFetch.start(); ntkinbbD
} bA^a@ lv a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8DI|+`OgW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7kwG_0QO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ti/iD2g
nEndPos = " + nFileLength); p4AXQuOP
// fileSplitterFetch[nPos.length-1].start(); e-K8K+7
oF6MV&q/
D&^:hs@
//等待子线程结束 {Jy%h8n*
//int count = 0; \rN_CBM
//是否结束while循环 bT*4Qd4W
boolean breakWhile = false; nRE}F5k
h1gb&?w5P
&4%J35~
while(!bStop) N^ET qg
{ '_&(Iwu
write_nPos(); dDuA%V0
Utility.sleep(500); `x#~-
breakWhile = true; uHIWbF<0oo
s+w<!`-
w0I /
for(int i=0;i<nStartPos.length;i++) R`?^%1^N
{ Uy1xNb/d
if(!fileSplitterFetch.bDownOver) [O)Zof
{ bYgYP|@
breakWhile = false; <EUSl|6
break; 7fEV/j
} U`Ag|R
} UKBMGzu2:
if(breakWhile) Sp )}
break; "$'~=' [
6K y;1$
5q#|sVT7R
//count++; yk)j;i4@
//if(count>4) 4Qo1f5>N
// siteStop(); Xda<TX@-
} iHn]yv3 #
wEbs E<</
eEh0T%9K
System.err.println("文件下载结束！"); -:>#w`H
} 7EO&:b]
catch(Exception e){e.printStackTrace ();} DnFl*T>
} htRZ}e
Pb;`'<*U
kC5,yj
//获得文件长度 n6Zx0ad?
public long getFileSize() |K-lgrA
{ y m{/0&7
int nFileLength = -1; )l}wjKfgO
try{ O*v+<|0!l
URL url = new URL(siteInfoBean.getSSiteURL()); M!l5,ycF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mwCnP8:K
httpConnection.setRequestProperty("User-Agent","NetFox"); e;'T?&t
~ 7Nyi dV;
v`w?QIB]
int responseCode=httpConnection.getResponseCode(); L _y|l5
if(responseCode>=400) Lp WEu^j
{ L# 1vf
processErrorCode(responseCode); S:uEK
return -2; //-2 represent access is error SkA'+(
} XXcf!~uO
.8!0biS
FxX3Pq8h
String sHeader; $:N "*
|P7f^0idk
` W>B8
for(int i=1;;i++) E|;5Z*
{ &RrQ()<as
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O*{H;7Pv
//Utility.log(in.readLine()); !q\w"p0X
sHeader=httpConnection.getHeaderFieldKey(i); 1n(}Q1fa
if(sHeader!=null) ;T+U&U0d|
{ s3Ce]MH
if(sHeader.equals("Content-Length")) ]r1{%:8
{ Lp)8SmN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D*gVS
break; JW[\"`x!
} ;j>d"i36&
} cgeS)C7
else mRY6[*u
break; uW9M&"C~
} kte.E%.PE
} C+?s~JL
catch(IOException e){e.printStackTrace ();} 7 aD&\?
catch(Exception e){e.printStackTrace ();} aQ:f"0fL
)o</gt)
-*fYR#VQQB
Utility.log(nFileLength); l_-n&(N2<[
N>Y50
Q_.c~I}yV
return nFileLength; /j/%wT2m
} 5@+Ei25
Z*>/@J}
f$|v0Xs
//保存下载信息（文件指针位置） o>-v?Ug
private void write_nPos() s7i.p]
{ cgXF|'yI&l
try{ cloSJmUlQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); e@-Mlq)
output.writeInt(nStartPos.length); dG?a"/MA
for(int i=0;i<nStartPos.length;i++) TK/'=8
{ W.D3$
// output.writeLong(nPos); `A _8nW)
output.writeLong(fileSplitterFetch.nStartPos); { DQE7kI
output.writeLong(fileSplitterFetch.nEndPos); `$SEkYdt
} AE4~M`6D
output.close(); #*$@_
} 7jH`_58
catch(IOException e){e.printStackTrace ();} ~yH>Ko9F}
catch(Exception e){e.printStackTrace ();} N$&ePU J
} K[gWXBP
<bZm
tZ j,A%<
//读取保存的下载信息（文件指针位置） :U.)YHY
private void read_nPos() rL sK-qQ
{ uBq3.+,x*
try{ 0s9z @>2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k)K-mD``U
int nCount = input.readInt(); q[OTaSQ~u^
nStartPos = new long[nCount]; xhkWKB/7
nEndPos = new long[nCount]; %"[dGB$S
for(int i=0;i<nStartPos.length;i++) X/8iJ-KB
{ ?wf+{x-dPP
nStartPos = input.readLong(); SslY]d]
nEndPos = input.readLong(); 5Vo}G %g
} ;;'a--'"
input.close(); Ji:iKkI
} 4<Sa,~4
catch(IOException e){e.printStackTrace ();} 7 Y>`-\
catch(Exception e){e.printStackTrace ();} MR_bq_)
} /Ej]X`F
MhI)7jj`mt
-?B9>6h"
private void processErrorCode(int nErrorCode) JD{MdhhV
{ ?6iatI !
System.err.println("Error Code : " + nErrorCode); _`Q It>R
} 0 {JK4]C
~d%;~_n
\}x'>6zr2
//停止文件下载 ff}a <w
public void siteStop() t0J5v;
{ Az< 9hk
bStop = true; yD"0=\
for(int i=0;i<nStartPos.length;i++) 2>}\XKF).
fileSplitterFetch.splitterStop(); xOL)Pjo/m
|^PLZ>
MFH"$t+
} [+l
} 0)oN[
//负责部分文件的抓取 l/ rZcf8z
**FileSplitterFetch.java TwuX-b
*/ Lubs{-5lk
package NetFox; (HaKF7Jsi
ft/^4QcyAM
<P^hYj-swh
import java.io.*; mheU#&|
import java.net.*; %]<RRH.w
\5[D7}
3IK(f.
public class FileSplitterFetch extends Thread { JOdwv4(3V
U$A7EFK'
|#&V:GZp
String sURL; //File URL 27a*H1iQ
long nStartPos; //File Snippet Start Position 0Ox|^V
long nEndPos; //File Snippet End Position [t.%&#baF
int nThreadID; //Thread's ID *F szGn<
boolean bDownOver = false; //Downing is over r6n5Jz
boolean bStop = false; //Stop identical Aa`MK$29F
FileAccessI fileAccessI = null; //File Access interface T")i+v
\+{t4Im
+qdIj] v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N2tkCkl^x9
{ dm2CA0
this.sURL = sURL; e$Bf[F#;-
this.nStartPos = nStart; :6W^ S/pf
this.nEndPos = nEnd; 7V=MRf&xQ
nThreadID = id; %K^gUd>,R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )8$:DW;
} {x[;5TM
NuD[-;N]
|)-|2cPRur
public void run() }. xrJ52Tz
{ B.YMP;7>
while(nStartPos < nEndPos && !bStop) B [+(r
{ 1 Itil~
v\%B
rv}mD
try{ 3ximNQ}S
URL url = new URL(sURL); 9k\)tWe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ut$,?k!M
httpConnection.setRequestProperty("User-Agent","NetFox"); Hwp{<
String sProperty = "bytes="+nStartPos+"-"; ={`CHCI
httpConnection.setRequestProperty("RANGE",sProperty); BIV<ti$.
Utility.log(sProperty); .kc"E
I7fb}j`/
$Ns,ts(ng
InputStream input = httpConnection.getInputStream(); J%\- 1
//logResponseHead(httpConnection); AfRW=&xdT
_%'L@[ H
eyT>wma0
byte[] b = new byte[1024]; R<;OEN
int nRead; x6^l6N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2e9jo,i
{ h(@R]GUX
nStartPos += fileAccessI.write(b,0,nRead); ^kn^CI6
//if(nThreadID == 1) yB,{#nM>8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p^1zIC>F
} `KpFH.k.K
c~}={4M]
bVoU|`c
Utility.log("Thread " + nThreadID + " is over!"); 7}4'dW.
bDownOver = true; 7G5y)Qb
//nPos = fileAccessI.write (b,0,nRead); , 3X: )
} TN35CaSmq
catch(Exception e){e.printStackTrace ();} F{k$Atb?g/
} BXg!zW%+
} >Mvka;T]
yiVG ]s
~:>AR` 9G
//打印回应的头信息 #:J:YMv
public void logResponseHead(HttpURLConnection con) Kt W6AZJ
{ {p`mfEE(
for(int i=1;;i++) q,B3ru.?d
{ e>l,(ql
String header=con.getHeaderFieldKey(i); FR x6c
if(header!=null) E *F*nd]K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9>by~4An?
Utility.log(header+" : "+con.getHeaderField(header)); &{%MjKJ._
else Ia629gi5s
break; `)R?nVb
} }q%jO
} 2_;]
nPcS3!7B#
i"vawxm
public void splitterStop() 'LVn^TB_f&
{ \dRzS@l
bStop = true; 6M ^IwE
} Ji;SY{~kv
@}<"N
Q%ruQ#
} 8|O=/m^]
N&T:Lt_N
43zUN
/* +TC1nkX
**FileAccess.java *>jjMyn
*//文件访问(定位，写) LA-_3UJx
package NetFox; #HeM,;Xp
import java.io.*; q-3]jHChh
ddsUz1%l
wGvhB%8K
public class FileAccessI implements Serializable{ zJ9v%.e
H@{Objh1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4j>fI)FUW
RandomAccessFile oSavedFile; #(C/Cx54
long nPos; W9Nmx3ve
Ia2(Km
?GdsOg^
public FileAccessI() throws IOException n~tqO!q
{ c-kA^z{f
this("",0); [*8Y'KX <
} B'-I{~'/
YOyp|%!
~-TOsRvxR
public FileAccessI(String sName,long nPos) throws IOException 8pXKO"u],
{ *8bK')W
oSavedFile = new RandomAccessFile(sName,"rw"); hq#kvvi{f
this.nPos = nPos; 9Bz0MUbrLl
oSavedFile.seek(nPos); <l$P&jSF3
} xCWz\-;
A\z`c e!
{Oj7
public synchronized int write(byte[] b,int nStart,int nLen) -gS"pE^1
{ jin db#)bz
int n = -1; #;[Bl=3(
try{ @%1IkvJV
oSavedFile.write(b,nStart,nLen); G?`-]FMO
n = nLen; ;+ azeW^
} 0VN7/=n|
catch(IOException e) zB*euHIqZ
{ W|MWXs5'1*
e.printStackTrace (); hN
} BOvF)4`
y,E.SB
5t\HJ`C1Z
return n; u%u&F^y
} _;hf<|c
gAt~?HvW6
s~^}F+n
} ~.^AL}zm_
?cKZ_c
VWx]1\
/* xzsdG?P
**SiteInfoBean.java IA4N@ijRxh
*/ .2W"w)$nuq
package NetFox; mT@nn,
n[,XU|2
|a-fE]{7
public class SiteInfoBean { 6)qp*P$L
qmglb:"
#(KDjnP[
private String sSiteURL; //Site's URL HeLG?6
private String sFilePath; //Saved File's Path p@~ic#X
private String sFileName; //Saved File's Name PT'MNH
private int nSplitter; //Count of Splited Downloading File 1vnYogL
, sjh^-;
thc <xxRP
public SiteInfoBean() _Mk7U@j+9
{//nSplitter的缺省值为5 +D&Pp0xe
//default value of nSplitter is 5 }rq9I"/L
this("","","",5); ?Q0I'RC
} KkcXNjPVS
h|D0z_f
zF`3gl.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rf.`h{!!
{ 8)L*AdDAW!
sSiteURL= sURL; /@"Y^
sFilePath = sPath; :"Y*<=x#2
sFileName = sName; I|9 SiZ0
this.nSplitter = nSpiltter; ~g6 3qs
w(9*7pp
",yc0 2<
} `JB?c
q_V0+qH
PLX>-7@
public String getSSiteURL() =-"c*^$]
{ NX[4PKJ0C
return sSiteURL; v+G=E2Lhv
} -F@L}|
aC%&U4OS
@n-r-Q
public void setSSiteURL(String value) )5_jmW`n
{ ^7^N}x@
sSiteURL = value; e}hmS1>H
} 'n;OB4
)G~w[~
V5i*O3a~
public String getSFilePath() 'Gl&Pa1g?
{ `R"~v/x
return sFilePath; jYRP8 Yi
} I_1e?\
I%j_"r9-I
PPkx4S_>
public void setSFilePath(String value) =K\r-'V
{ *=AqM14 @
sFilePath = value; Fv74bC%
} h[o6-f<D
q1?&Ev^
s{0aBeq
public String getSFileName() 8NBT|N~N
{ m3bCZ9iE
return sFileName; ) ZfdQ3
} y5r4+2B
\xv;sl$f
Fqy\CMC
public void setSFileName(String value) t.p~\6Yi
{ 5Xn.CBd]
sFileName = value; ]\ !5}L
} R:X0'zeRr
T*g:# ^4
i|`dWOVb
public int getNSplitter() ]:>,A@7
{ i4JqT\q
return nSplitter; Gg Jf7ie4
} +M' H0-[
_{<seA
/!h;c$
public void setNSplitter(int nCount) _g%TSumvq<
{ B"yFS7Rrj
nSplitter = nCount; )R`xR,H
} [AMAa]^
} 1#IlWEg
I/Jb!R ~
|a1{ve[
/* k:jSbbQ
**Utility.java I[)%,jd
*/ mKrh[nA
package NetFox; h2ytS^
&xRo^iV?
Q></`QWpoB
public class Utility { L:XC
X+UJzR90
*na?n2Yzt
public Utility() c\a_VRN>r
{ '5&s=M_
.<@8gNm3
#@<9S{F
} [8tL"G6s
^[:p|U2mA
//线程睡眠 _SW3_8SuM.
public static void sleep(int nSecond) ;rc`OZyE
{ i&{DOI%w
try{ MxT-1&XL
Thread.sleep(nSecond); |$?bc3
} _ODbY;M
catch(Exception e) ,eTU/Q>{,&
{ T5a*z}L5
e.printStackTrace (); /c uLc^(X
} lpz2 m\
} PRHCrHs
Fu!RhsW5j
//日志 J8mdoVt
public static void log(String sMsg) SkmT`*v@
{ dFKM 8_jH
System.err.println(sMsg); ^0/j0]O
} ;L']e"G
CrwwU7qKL
5[c^TJ3
public static void log(int sMsg) feQ **wI
{ +v=C@2T
System.err.println(sMsg); |PC*=ykT3
} j~!X;PV3
} ~l)-wNqR4r
w.[ "p9tc
~ 4kc/a
/* #B4%|v;`E?
**TestMethod.java T}8Y6N<\m
*/ 8F'x=lIO
package NetFox; '&\kxNglJ
h*-Pr8
z CvKDlL
public class TestMethod { PYGRsrcFd#
)jt #=9ZQ
A!h`]%0B
public TestMethod() D8$G`~hD
{ ///xx/weblogic60b2_win.exe ZMel{w`n
try{ [eC2"&}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <yd{tD$A*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3\XU_Xs(]
SiteFileFetch fileFetch = new SiteFileFetch(bean); *s:(jDlv
fileFetch.start(); r-Pkfy(
} H'
catch(Exception e){e.printStackTrace ();} UEguF&
ljb7oA3cP4
[PDNwh0g5
} m6w].-D8
p>4-s, W
dw*_(ys
public static void main(String[] args) XCBL}pNkR
{ >Wv;R2|
new TestMethod(); A<??T[
} ~^1{B\I
} CLUW!F
点击下载更多相关资料