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)); LJ+Qe%|
} mOE%:xq9-
for(int i=0;i<nEndPos.length-1;i++) Ed+"F{!eQ
{ ">hOD'PG
nEndPos = nStartPos[i+1]; b%"Lwqdr7
} TX7]$Wj
nEndPos[nEndPos.length-1] = nFileLength; Cp[ NVmN
} j& ~`wGM
} 6|AD]/t^K
M^3pJ=;5
qt{{q
//启动子线程 RJO40&Z<Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v cZg3:j
for(int i=0;i<nStartPos.length;i++) :UDT! 5FNO
{ B`i5lD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q#!]5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JOvRUDZ
nStartPos,nEndPos,i); <C6*-j1oz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AHl1{* [
fileSplitterFetch.start(); [d}AlG!
} 7GVI={b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z[pMlg6Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /Xo8 kC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N6wCCXd
nEndPos = " + nFileLength); ]> 36{k]&
// fileSplitterFetch[nPos.length-1].start(); ic]b"ItD
\C eP.,<
>Qg 9KGk'
//等待子线程结束 W]U},g8Z
//int count = 0; _)6N&u8
//是否结束while循环 { i2QLS
boolean breakWhile = false; By7?<A
d9kN@W
klwNeGF]N
while(!bStop) 3sy|pa
{ Sp>v`{F
write_nPos(); /;rPzP4K6
Utility.sleep(500); SB#Y^!
breakWhile = true; Vim*4^[#L
@#CZ7~Hn
8BgHoQ*
for(int i=0;i<nStartPos.length;i++) oR_qAb
{ 1QPS=;|)
if(!fileSplitterFetch.bDownOver) #y:,owo3I
{ m_pqU(sP
breakWhile = false; ~qP_1() ?
break; SV}C]<
} ZI>')T<@j"
} ,2C{X+t
if(breakWhile) gvLzE&V}
break; ?5e]^H}
,9@JBV%_
K,'v{wSr
//count++; OqcM3#
//if(count>4) W-UMX',0zS
// siteStop(); 0/@ ^He8l
} IVblSiFF
-4IHs=`;I
/suW{8A(E
System.err.println("文件下载结束！"); 2S^:fm}
} rrL gBeQa
catch(Exception e){e.printStackTrace ();} 8\H*Z2yF+
} 9KgGK cy%
Gi=s|vt
Jv+N/+M47
//获得文件长度 @V>BG8Y
public long getFileSize() jFr[T
{ d%wy@h
int nFileLength = -1; 8uZM%7kI6+
try{ fKYRDGn
URL url = new URL(siteInfoBean.getSSiteURL()); 4,)EG1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O7of9F~"
httpConnection.setRequestProperty("User-Agent","NetFox"); H/?@UJ5m
RL|d-A+;
X{YY)}^
int responseCode=httpConnection.getResponseCode(); a?dUJt
if(responseCode>=400) o6 lCP&
{ fC7rs5
processErrorCode(responseCode); $t{;- DpNB
return -2; //-2 represent access is error 'Jl |-RUd
} 7}r6mr0vpm
"7X[@xX@
{k"t`uo_
String sHeader; 9>I&Z8J$M
(O@fgBM
<Mq vGXI
for(int i=1;;i++) 7XU$O$C
{ ](2\w9i%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L)qDtXd4
//Utility.log(in.readLine()); $]`rWSYtv`
sHeader=httpConnection.getHeaderFieldKey(i); R|u2ga~
if(sHeader!=null) c`E0sgp
{ |@*3 nb8
if(sHeader.equals("Content-Length")) Ua2waA
{ wS"`~Ql_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dm+[cA"I
break; :H(wW
} Q dPqcw4+X
} H,q-*Kk
else +~[>Usf
break; 3Ud{W$Ym
} !+(c/ gwBh
} gx ]5)O
catch(IOException e){e.printStackTrace ();} y`Nprwb
catch(Exception e){e.printStackTrace ();} <<M1:1
LyuA("xB#
Zk:_Yiki&
Utility.log(nFileLength); qvs&*lBY
>f*-9
RoLN#
return nFileLength; 089 <B& <
} ]p-xds#d
w}WfQj
=v:}{~M^$
//保存下载信息（文件指针位置） vXLGdv::
private void write_nPos() Mc@_[q!xY?
{ kuI$VC
try{ JUpb*B_z
output = new DataOutputStream(new FileOutputStream(tmpFile)); pt_]&3\e
output.writeInt(nStartPos.length); vKFEA7
for(int i=0;i<nStartPos.length;i++) [fZhfZ)<
{ lK%)a +2
// output.writeLong(nPos); <To$Hb,NP
output.writeLong(fileSplitterFetch.nStartPos); F6Ne?[b
output.writeLong(fileSplitterFetch.nEndPos); %)#yMMhR
} e,DRQ2AU
output.close(); 5I>a|I!j
} s^R$u"pFs
catch(IOException e){e.printStackTrace ();} 3\2^LILLO
catch(Exception e){e.printStackTrace ();} eZdFfmYW^R
} 9cXL4
UpSa7F:Uw
qp{3I("_
//读取保存的下载信息（文件指针位置） V M{Sng
private void read_nPos() *ORa@x
{ L}UrI&]V$:
try{ ,~G:>q$ad
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q>g-xe 1
int nCount = input.readInt(); <0btwsv}
nStartPos = new long[nCount]; H.]p\UY9
nEndPos = new long[nCount]; 044Q>Qz,
for(int i=0;i<nStartPos.length;i++) JE_GWgwdv
{ aHkt K/
nStartPos = input.readLong(); -,qGEJ
nEndPos = input.readLong(); AK//]
} a^eR~efdu@
input.close(); Txa 2`2t7
} 1deK}5'
catch(IOException e){e.printStackTrace ();} %zYTTPLZ
catch(Exception e){e.printStackTrace ();} xFA+ZjBC
} Pah*,
/:ju/~R}
qS/ 'Kyp_
private void processErrorCode(int nErrorCode) 4Dw| I${O
{ k[a5D/b
System.err.println("Error Code : " + nErrorCode); sp7#e%R\
} -#`tS
ZfU &X{
_Rk>yJD7s
//停止文件下载 Ch'e'EmI
public void siteStop() ]vjMfT%]W
{ T?KM}<$(O
bStop = true; },%,v2}
for(int i=0;i<nStartPos.length;i++) S76xEL
fileSplitterFetch.splitterStop(); $VJE&b
4bq+(CI6
\F9HsR6
} [H=l#W@
} <Q@{6
//负责部分文件的抓取 ?8ady% .ls
**FileSplitterFetch.java H8A=]Gq
*/ h3(B7n7
package NetFox; \=j|ju3
:a*F>S!
LM*m>n*
import java.io.*; ')Qb,#/,%
import java.net.*; 7,3 g{8
L"'L@A|U
BYZllwxwTE
public class FileSplitterFetch extends Thread { J:dNV<A^
"u3 N9
>K 7]G?+7E
String sURL; //File URL , L5.KwB
long nStartPos; //File Snippet Start Position (Eo#oX
long nEndPos; //File Snippet End Position R_duPaWc@
int nThreadID; //Thread's ID fO}Y$y\q
boolean bDownOver = false; //Downing is over k8w:8*y'.
boolean bStop = false; //Stop identical 4`p[t;q
FileAccessI fileAccessI = null; //File Access interface vFK!LeF%
]//Dd/L6
RJE<1!{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [(iJj3s!
{ W:1GY#Pe
this.sURL = sURL; kj@m5`G
this.nStartPos = nStart; :o_6
this.nEndPos = nEnd; zvKypx
nThreadID = id; kYu"`_n}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !$!"$-5
} E@8&#<
G\Q0{4w8
}b/G{92
public void run() fH 0&Wc3yC
{ RQCKH]&!
while(nStartPos < nEndPos && !bStop) |$`I1
{ @\Yu?_a
V3[>^ZCA
x<>In"QV
try{ /S`d?AV
URL url = new URL(sURL); e[%g'}D:-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ktiC*|fd
httpConnection.setRequestProperty("User-Agent","NetFox"); |c:xK{Ik
String sProperty = "bytes="+nStartPos+"-"; ~c|{PZ9U
httpConnection.setRequestProperty("RANGE",sProperty); N=;VS-
Utility.log(sProperty); N Bpf
6@J)kV
$jN,]N~
InputStream input = httpConnection.getInputStream(); /;9]LC.g
//logResponseHead(httpConnection); 0[!38
''wF%q
QO3QR/Ww
byte[] b = new byte[1024]; +\~Mx>Cn
int nRead; *!u a?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K2ry@haN
{ ZJ}|t
nStartPos += fileAccessI.write(b,0,nRead); "uD^1'IW2
//if(nThreadID == 1) z/t+t_y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z$ 6yB
} /Avl&Rd
E{E%nXR)
:\,3=suWq
Utility.log("Thread " + nThreadID + " is over!"); =xPBolxm5U
bDownOver = true; Y 9~z7
//nPos = fileAccessI.write (b,0,nRead); usOIbrQ
} &&($LnyA]
catch(Exception e){e.printStackTrace ();} `KJBQK
} v1~`76^
} v`9n'+h-c6
<rFKJ^B
r?wE;gH
//打印回应的头信息 -,}ppTG
public void logResponseHead(HttpURLConnection con) M\jTeB"Z
{ 2Ls
for(int i=1;;i++) \7A6+[ `fa
{ m'ykDK\B
String header=con.getHeaderFieldKey(i); *m`KY)b=l
if(header!=null) Auf2JH~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jl~?I*Gr
Utility.log(header+" : "+con.getHeaderField(header)); &ajpD sz;
else ($Y6hn+
break; a%)-iL X8&
} |T^c(RpOE
} R{A$hnhW6
MYF6tZ*
nh+f,HtSt
public void splitterStop() . [5{
{ f iu?mb=*
bStop = true; jwZBWt )5
} w65D;9/;
G9P)Y#WB
nK5FPFz8
} &[4lP~
K(B|o6[
gv,8Wo
/* :,BKB*a\
**FileAccess.java }dO^q-t$3
*//文件访问(定位，写) 9?#L/
package NetFox; K\`>'C2_V
import java.io.*; s6J`i&uu
1b-_![&]1
tN:PWj5
public class FileAccessI implements Serializable{ nnPY8pdjSD
%{ToWLb{I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C"!k`i=Lj
RandomAccessFile oSavedFile; ds"q1
long nPos; sZ9VXnz24
)I`Ma6bX
Zqnwf
public FileAccessI() throws IOException x-HN]quhe
{ x)Ls(Xh+g
this("",0); vZl]C%
} qg#|1J6e
~kW[d1'c
+>wBGVvS
public FileAccessI(String sName,long nPos) throws IOException FOx&'dH%@
{ O$,MdhyXC
oSavedFile = new RandomAccessFile(sName,"rw"); >|@i8?|E
this.nPos = nPos; ~i y]X:U
oSavedFile.seek(nPos); ?#0|A?U
} 0O:')R&
[:(^n0%
_M;M-hk/
public synchronized int write(byte[] b,int nStart,int nLen) Uc?#E $X
{ oWo/QNw9
int n = -1; WVfwt.Y
try{ H~Fb=.h]U
oSavedFile.write(b,nStart,nLen); kKP<K+hH
n = nLen; 5x:dhkW
} @fSBW+
catch(IOException e) =1'vXPv`
{ ]1(G:h\
e.printStackTrace (); -*T<^G;rK
} d`+@ _)ea
n^2p jTkl
M$0-!$RY
return n; _#]/d3*Z}
} lEe<!B$d"
A\v(!yg
@ =M:RA
} ,_(AiQK
8A ;)5!
_`(WX;sK
/* n$O[yRMI[
**SiteInfoBean.java hPB^|#}
*/ <//#0r*
package NetFox; d1rIU6
7A mnxFC
F$k^px
public class SiteInfoBean { ?'$Yj>R6
?' :v):J}
awic9uMH
private String sSiteURL; //Site's URL BQ7p<{G
private String sFilePath; //Saved File's Path H]x-s
private String sFileName; //Saved File's Name /$ :w8
private int nSplitter; //Count of Splited Downloading File )Z0bMO<
yxx'g+D*
GF=rGn@,)`
public SiteInfoBean() B3V;
{//nSplitter的缺省值为5 HDY2<Hzc
//default value of nSplitter is 5 e 1$<,.>
this("","","",5); aF41?.s
} ,p\:Z3{ZH
Adma~]T9
^L@2%}6b`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e: aa
{ d~F4
sSiteURL= sURL; .*(xkJI3
sFilePath = sPath; 4Lb!Au|Y
sFileName = sName; ~0 Ifg_G
this.nSplitter = nSpiltter; hE|W%~Jx
&Q`{ Gk
C3"5XR_Ov
} j@HOU~x
'fIoN%
0lm7'H*~
public String getSSiteURL() H-|%\9&{S
{ Ap<kK0#h
return sSiteURL; ZZu{ct9
} :+qd>;yf#
7H l>UX,|
h/*q +H
public void setSSiteURL(String value) ,|RN?1?U
{ L]kd.JJvy
sSiteURL = value; !w;oVPNg
} =+z+`ot
HPz3"3n!
:yi?<
public String getSFilePath() {gkzo3
{ EQTJ=\WFF
return sFilePath; 6^l|/\Y{
} w5+H9R6
+ ;LO|!
lPyY
public void setSFilePath(String value) J_S8=`f%
{ r&y0`M
sFilePath = value; 31^Jg
} qC x|}5:
Kt#_Ln_6
uSgR|b;R]
public String getSFileName() YstR T1
{ (xdC'@&
return sFileName; e1OGGF%En
} $Vp*,oRL
.US=fWyrb
~~\C.6c#
public void setSFileName(String value) H-&T)
{ v6C$Y+5~
sFileName = value; e=^^TX`I
} 2Wn*J[5
K'_qi8Z
\]8F_K
public int getNSplitter() uo8[,'
{ VtN1 [}
return nSplitter; \'Q rJ ?D
} CBr(a'3{Z
3%[;nhbA7
g2;lEW
public void setNSplitter(int nCount) ;p+[R+ )
{ [eO^C
nSplitter = nCount; :;hz!6!
} 7,lnfCm H
} lsaA
abD@0zr
lDSF
/* xwF mY'o
**Utility.java 3Cw}y55_y
*/ %vil~NU
package NetFox; YSh@+AN
0,/I2!dF?
jQrj3*V
public class Utility { vc0LV'lmg
er8T:.Py
; I;&O5Y
public Utility() SF=TG84<
{ $niG)@*
Kr5(fU
AP:Q]A6}
} I`f5)iF?0
\$4 [qG=
//线程睡眠 ]t0St~qUL)
public static void sleep(int nSecond) J%u,qF}h
{ 'Qh1$X)R7a
try{ T-LX>*
Thread.sleep(nSecond); kV+%(Gl8
} c'.XC}
catch(Exception e) lvsj4cT
{ !-t,r%CG
e.printStackTrace (); "Ccyj/
} 16ZyLt
} `Gj(>z*
dEZUK vo
//日志 lrAhdi
public static void log(String sMsg) -VeCX]
{ xg}Q~,:
System.err.println(sMsg); 0NeIQr1N_
} *`q?`#1&&.
", p5}}/
%tMx48'N
public static void log(int sMsg) lSg[7lt
{ !:PiQ19 'u
System.err.println(sMsg); -.Blj<2ah
} _%[po%]
} YF)]B|I
mqj-/DN6*
~Pj q3etk
/* (3"N~\9m
**TestMethod.java %.m+6 zaF
*/ ZTibF'\5N
package NetFox; -&COI-P8
XEnu0gr
W=#AfPi$&
public class TestMethod { }v's>Ae~p
OXm`n/64+
T](}jQxj`
public TestMethod() RG*Vdom
{ ///xx/weblogic60b2_win.exe $AT@r"
try{ 9QaE)wt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?ac4GA(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z\$M)e8n
SiteFileFetch fileFetch = new SiteFileFetch(bean); -V4%f{9T3
fileFetch.start(); QgI[#d{
} y^"@$
catch(Exception e){e.printStackTrace ();} p- a{6<h
iy8Jl
0,nz*UDk
} -V:HT j
,3!$mQL=
*E*oWb]H
public static void main(String[] args) {zWR)o .=
{ 9b/Dswxjx
new TestMethod(); ESNI$[`
} @ 5^nrB
} -OSj<m<
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