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)); }H#C<:A
} _uXb 9
for(int i=0;i<nEndPos.length-1;i++) Cb4.N8
{ \/XU v(
nEndPos = nStartPos[i+1]; %f)%FN.S
} 79&=MTM
nEndPos[nEndPos.length-1] = nFileLength; C#qF&n
} i.Rxx, *?
} pyUzHF0
Fs$mLa
B:)PUBb
//启动子线程 P5Bva
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G*s5GG@Z.
for(int i=0;i<nStartPos.length;i++) SI`ems{1>c
{ vVhSl$mW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mzO5&h7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CwjKz*'[g
nStartPos,nEndPos,i); i[Qq,MmC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); / jLb{Ky
fileSplitterFetch.start(); ]hMs:$}
} g3|k-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8Y"R@'~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E]w2 {%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?_-5W9
nEndPos = " + nFileLength); sA~Ijg"6
// fileSplitterFetch[nPos.length-1].start(); D`'h8:\
.(^%M 2:6
vRkVPkZ6|
//等待子线程结束 V~#8lu7;
//int count = 0; Tuz~T _M
//是否结束while循环 ]qb>O:T
boolean breakWhile = false; ajCe&+
Z-j?N{3&
fQU5'wGp
while(!bStop) cb=ixn
{ %E8HLTEvl
write_nPos(); ~@#s<a,%;
Utility.sleep(500); j'x@P+A
breakWhile = true; -!lSk?l
g es-nG-
lb{X6_.
for(int i=0;i<nStartPos.length;i++) !c"EgP+
{ uS<og P
if(!fileSplitterFetch.bDownOver) qWU59:d^{
{ y@h v#;
breakWhile = false; Xv+!)j<
break; QVF561Yz
} yi8AzUW cW
} fBb:J+
if(breakWhile) !k<k]^Z\
break; vYybQ&E/
FwE<_hq//
C%#w1k
//count++; #/"Tb^c9
//if(count>4) C>Q|"Vf2
// siteStop(); %H[~V f?d
} e/uLBZ
Alv"D
8UzF*gS
System.err.println("文件下载结束！"); Xz?7x0)Z
} !q~f;&rg
catch(Exception e){e.printStackTrace ();} fh*7VuAc
} ZcHd.1fXh
!<&To
]n!oa
//获得文件长度 u+9)B 6O1
public long getFileSize() 6<%b}q9Mo
{ ~Qd|.T
int nFileLength = -1; au E8 ^|
try{ HBNX a
URL url = new URL(siteInfoBean.getSSiteURL()); HXN. ,[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vA{DF{S4
httpConnection.setRequestProperty("User-Agent","NetFox"); }tW1\@ =
wE-y4V e
g)ofAG2
int responseCode=httpConnection.getResponseCode(); SmS6B5j\R
if(responseCode>=400) i# fvF)
{ A4*D3\>%u
processErrorCode(responseCode); D;hJK-Y
return -2; //-2 represent access is error 6>3zD)tG
} de9e7.(2
zjTCq; G
peew<SX
String sHeader; WOeG3jMz?
(Z0.H3
9e7):ZupO
for(int i=1;;i++) 8lyNg w1
{ FzOlM-)m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v8 II=9
//Utility.log(in.readLine()); </B:Zjn
sHeader=httpConnection.getHeaderFieldKey(i); %EYh*g{G
if(sHeader!=null) gW?Hd/
{ g7w#;E
if(sHeader.equals("Content-Length")) o4^#W;%w
{ BC85#sbl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I-Q(kWc
break; L<G6)'5W
} i)/#u+Y1P
} (S?qxW?
else M<x><U#]A
break; ?y@;=x!'
} |RBL5,t^
} a# Uk:O!
catch(IOException e){e.printStackTrace ();} C,8@V`
catch(Exception e){e.printStackTrace ();} g2vt(Gf;
F ~e}=Nb
*l@T 9L[M'
Utility.log(nFileLength); Odm1;\=Eg+
rcf#8
VrKLEN\
return nFileLength; MH]?:]K9V
} 'X\C/8\
DB'3h7T
1lsg|iVz
//保存下载信息（文件指针位置） -j^G4J
private void write_nPos() _QtW)\)5\
{ o9v.]tb
try{ wuhL r(
output = new DataOutputStream(new FileOutputStream(tmpFile)); {)4@rM
output.writeInt(nStartPos.length); +3pfBE|
for(int i=0;i<nStartPos.length;i++) MnQ 6 !1Z
{ ]>0$l _V
// output.writeLong(nPos); >w1jfpQ@t$
output.writeLong(fileSplitterFetch.nStartPos); ;p"#ZS7
output.writeLong(fileSplitterFetch.nEndPos); <^+&A7Q-_
} BPy pA$
output.close(); M2A3]wd2a
} oMxpdG3y-
catch(IOException e){e.printStackTrace ();} S,s") )A1
catch(Exception e){e.printStackTrace ();} (9)uZ-BF,
} [C3wjYi
D7v.Xq|
}cIj1:
//读取保存的下载信息（文件指针位置） t?p>L*
private void read_nPos() v){X&HbP
{ r2&/Ii+
try{ W,%qL6qV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zB"y^g
int nCount = input.readInt(); 3P*"$fH
nStartPos = new long[nCount]; rY"EW"y
nEndPos = new long[nCount]; 'l1cuAP!+
for(int i=0;i<nStartPos.length;i++) InG<B,/W?
{ ^Uldyv/
nStartPos = input.readLong(); K&&YxX~3
nEndPos = input.readLong(); ]2z Gb5s"
} NV^n}]ci
input.close(); xQ=L2pX
} ,f .#-
catch(IOException e){e.printStackTrace ();} kCKCJ}N
catch(Exception e){e.printStackTrace ();} VKr oikz@]
} &RlYw#*1.
8yGo\\=T
aVn+@g<.
private void processErrorCode(int nErrorCode) {z# W-
{ (k %0|%eR
System.err.println("Error Code : " + nErrorCode); L ~$&+g
} H"rIOoxf
Bs-MoT!
."j*4
//停止文件下载 (!<G` ;}u
public void siteStop() =YR+`[bfI
{ n(\VP!u5r
bStop = true; Wp=:|J
for(int i=0;i<nStartPos.length;i++) 0urM@/j+
fileSplitterFetch.splitterStop(); P'k`H
68!=`49r>
IUy5=Sl
} 1c $iW>0K
} T)cbpkH4
//负责部分文件的抓取 gk"J+uM
**FileSplitterFetch.java 9riKSp:5
*/ ="[6Z$R
package NetFox; m6 a@Y<
Va\?"dH>M
!xD_=O
import java.io.*; 28o!>*
import java.net.*; SVT'fPm1M
}/z\%Y
4!<[5+.
public class FileSplitterFetch extends Thread { Oc^bbC
4Bq4d.0
Z9lfd6MU,
String sURL; //File URL OSCeTkR
long nStartPos; //File Snippet Start Position MtK5>mhZI`
long nEndPos; //File Snippet End Position ;gW?Fnry;
int nThreadID; //Thread's ID nB ,&m&
boolean bDownOver = false; //Downing is over b.v^:M
boolean bStop = false; //Stop identical 9,Ug
FileAccessI fileAccessI = null; //File Access interface j*1O(p+
?;Ge/~QU5
f@J-6uQ7w
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C9cQ} j:
{ 4";[Xr{pW
this.sURL = sURL; ,:/3'L
this.nStartPos = nStart; [3hOc/]s
this.nEndPos = nEnd; 2d-C}&}L\
nThreadID = id; f<( ysl1[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4+r26S,T
} Psu*t%nQ?A
GwZ(3
btU:=6
public void run() 2o-Ie/"d\
{ X6: c-
while(nStartPos < nEndPos && !bStop) jiAN8t*P
{ 3+r8yiY
Uzd\#edxJ
SN|:{Am
try{ v"smmQZik
URL url = new URL(sURL); G |vG5$Nf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 97(*-e=e
httpConnection.setRequestProperty("User-Agent","NetFox"); . vQCX1V(
String sProperty = "bytes="+nStartPos+"-"; j*N:Kdzvl
httpConnection.setRequestProperty("RANGE",sProperty); JIU=^6^2'
Utility.log(sProperty); R>. %0%iq
)~[hf,R5S
p'IF2e&z
InputStream input = httpConnection.getInputStream(); "# BI"
//logResponseHead(httpConnection); -AxO1 qO
[O(8izv
<lwkjt=RV
byte[] b = new byte[1024]; khtSZ"8X
int nRead; ~uz4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2:l8RH!Y
{ KZSvT{
nStartPos += fileAccessI.write(b,0,nRead); )]5}d$83
//if(nThreadID == 1) }W k!):=y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QWV12t$v
} -?68%[4lm_
-.X-02
QGQ>shIeZ
Utility.log("Thread " + nThreadID + " is over!"); IXef}%1N?
bDownOver = true; [.NG~ cpb
//nPos = fileAccessI.write (b,0,nRead); )R'~{;z }
} Qtpw0t"
catch(Exception e){e.printStackTrace ();} DZ Q=Sinry
} Ljjuf=]
} Th)Z?\8zk
/<$\)|r
&*N;yW""f
//打印回应的头信息 F"Y.'my8
public void logResponseHead(HttpURLConnection con) [<M~6]
{ Q)s[ls
for(int i=1;;i++) ^p433
{ Q4,!N(>D
String header=con.getHeaderFieldKey(i); 3ud_d>
if(header!=null) 3@/\j^U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h+7THMI
Utility.log(header+" : "+con.getHeaderField(header)); kKqb:
else Vyqj)1Z8>
break; F"<TV&xf
} &{c.JDO
} hf~'EdU
.v{ok,&
o1kY|cnGH
public void splitterStop() 89[5a
{ ub/9T-#l
bStop = true; +bw>9VmG
} hc;8Vsa
(/r l\I
9zKrFqhNo
} cn$o$:tW
RHc-kggk!
V94eUmx>?+
/* ZCAdCKX|
**FileAccess.java kgV_*0^
*//文件访问(定位，写) eJJD'Z
package NetFox; rv\m0*\<
import java.io.*; N1 }#6YNw
7xIXFuu
.A. VOf_
public class FileAccessI implements Serializable{ "[rChso
Hq*\,`b&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uwcm%N;I"
RandomAccessFile oSavedFile; Gb\Nqx(
long nPos; 8AK=FX&@&
^T#bla893
#ONad0T;
public FileAccessI() throws IOException .W#-Cl&n8
{ Oist>A$Z
this("",0); S}Q/CT?au
} VM1`:1Z:$
ebSG|F
mu[:b
public FileAccessI(String sName,long nPos) throws IOException msyC."j0jU
{ qBKRm0<W
oSavedFile = new RandomAccessFile(sName,"rw"); 1'[RrJ$Q
this.nPos = nPos; 0#AS>K5
oSavedFile.seek(nPos); a9ko3L
} 4Y)rgLFj
*,:>EcDr
q*|H*sS
public synchronized int write(byte[] b,int nStart,int nLen) Sd!!1as
{ #JFTD[1
int n = -1; 3$u3ssOL
try{ n\v;4ly^
oSavedFile.write(b,nStart,nLen); E*!
n = nLen; p=7{
} QU]&q`GE
catch(IOException e) fZqqU|tq
{ rfgkw
e.printStackTrace (); l$PSID
} ^]&uMkPN
)]/gu\90
kPm{tc
return n; ETw7/S${
} QgZwU$`p0
o"te7nBI
"%o,P/<X
} QUPZe~G>L
Nq`@ >Ml
eD4qh4|u.
/* B^;P:S<yG
**SiteInfoBean.java G234UjN%
*/ M7O5uW`
package NetFox; ^usZ&9"@P
J4yL"iMt
ZPktZ
public class SiteInfoBean { 6`>WO_<z
o7/S'Haxc]
E<j}"W$a
private String sSiteURL; //Site's URL p(jY2&g
private String sFilePath; //Saved File's Path /k$h2,O"*
private String sFileName; //Saved File's Name M.|cl#
private int nSplitter; //Count of Splited Downloading File hV(>}hb
|Va*=@&6J
U7)#9qS4
public SiteInfoBean() gn2*'_V~3
{//nSplitter的缺省值为5 $2p=vi3
//default value of nSplitter is 5 otA59 ;Z
this("","","",5); -YXNB[C
} }e7os0;s
o$*aAgS+
gRnn}LL^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,g.*Mx`-
{ 'pCZx9*c
sSiteURL= sURL; k$u\\`i]oC
sFilePath = sPath; DChqcdx~~
sFileName = sName; {XHAQ9'
this.nSplitter = nSpiltter; PTU_<\
V`/E$a1&
qc(R /[
} C 2f=9n/
qO;.{f
aC\O'KcH
public String getSSiteURL() 9g7d:zG
{ y&ZyThqg
return sSiteURL; #.<Uy."z2
} 03ol6y )C
#ujry.m
J`E,Xw>2
public void setSSiteURL(String value) `D44I;e^1;
{ q*L>MV
sSiteURL = value; (Dy6I;S
} >@b]t,rrK
9H~2 iW,Q;
jGg,)~)Y
public String getSFilePath() wzXIEWJ
{ ?QDHEC62
return sFilePath; iyA=d{S;V
} ~XzT~WxW
;PS V3Zh
$?_/`S13
public void setSFilePath(String value) rr@h9bak;g
{ Vu0d\l^$
sFilePath = value; zBQV2.@
} wMW."gM|
lOp7rW]$
Oe)d|6=
public String getSFileName() &kR*J<)V
{ 8t1XZ
return sFileName; S55h}5Y
} O'm5k l
&z;bX-"E
TANv)&,|9
public void setSFileName(String value) _>8rTk`/h
{ _#UiY ffa*
sFileName = value; 9QQiIi$74U
} Dias!$g
Wc*jTip
V-{3)6I$hG
public int getNSplitter() R]h3a:ic
{ t@&U2JaL>W
return nSplitter; /5!0wxN
} ag_*Z\
.+07 Ui]I!
z4qc)- {L
public void setNSplitter(int nCount) URd0|?t9^L
{ H;h$k]T
nSplitter = nCount; w)rd--9f
} bu?4$O
} P<%}!Y
W\c1QY$E
_o52#Q4
/* YE*%Y["
**Utility.java r|_@S[hZg
*/ AMw#_8Y
package NetFox; K7 J RCLA
Q$yMU[l)
5%_aN_1?ef
public class Utility { 22T\-g{
K8=jkU
Sx0/Dm
public Utility() hCOCX_
{ iV$TvD+
oH,{'S@q
gTS}'w{
} @*9c2\"k
6MD9DqD
//线程睡眠 4St-Q]Y _
public static void sleep(int nSecond) &-$27
{ 4,P(w+
try{ VnYcqeCm
Thread.sleep(nSecond); 83adnm
} /fSsh;F
catch(Exception e) 8\X-]Gh\^
{ 2Ij,OIcdBE
e.printStackTrace (); Op'&c0l
} :cxA
} EY`]""~8v
${h1(ec8
//日志 Y#5v5
public static void log(String sMsg) J2Mq1*Vpq
{ {E;oirv&
System.err.println(sMsg); ri`;
} *mJ\Tzc)
64L;np>
f<{f/lU@
public static void log(int sMsg) 2oF1do;
{ Z[9t?ePL
System.err.println(sMsg); i'QR-B&Z
} .iC!Ttr
} N/!(`Z,
]$,3vYBf
*EwDwS$$
/* <}p]0iA
**TestMethod.java WfXwI 'y
*/ G=F_{z\}
package NetFox; +lXIv
;:,U]@
?Rk[P cX<
public class TestMethod { uznYLS
8B(=Y;w
[}=a6Q>)
public TestMethod() DbSR(:
{ ///xx/weblogic60b2_win.exe VRZqY7j}g
try{ 95E#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R/xT.EQ(N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;X N Ahg7
SiteFileFetch fileFetch = new SiteFileFetch(bean); rb*0YCi
fileFetch.start(); wmA TV/
} jLA)Y [h
catch(Exception e){e.printStackTrace ();} 8(ot<3(D
o-o -'0l
sd"eu
} gZ|!'
UcKVLzKs
MH|F<$42
public static void main(String[] args) ifNyVEHy
{ NcrBp(
new TestMethod(); i6f42]Jy
} 4H^ACw
} 2^=8~I!n&
点击下载更多相关资料