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)); "ywh9cp
} C'!;J
for(int i=0;i<nEndPos.length-1;i++) Y(+^;Y3U
{ -wv6s#"u
nEndPos = nStartPos[i+1]; K9kUS
} >z%Q>(F
nEndPos[nEndPos.length-1] = nFileLength; M^7MU}5w
} HJC(\\~
} z*a8sr
WA$>pG5s
DS2)@
//启动子线程 S/`%Q2za4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6ATtW+sN]
for(int i=0;i<nStartPos.length;i++) #"ftI7=42
{ +xXH2b$wWC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Nk;iiz+_p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <X_!x_x
nStartPos,nEndPos,i); BT_tOEL#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IhiGP {
fileSplitterFetch.start(); 1 Vy,&[c~"
} '>k{tPi.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g2R@`./S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kL90&nP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", QJW`}`R
nEndPos = " + nFileLength); >m'x8xB=
// fileSplitterFetch[nPos.length-1].start(); 8CC/BOe
tQ~WEC
W0zbxJKjd
//等待子线程结束 hKlZi!4J
//int count = 0; e.o;eD}"
//是否结束while循环 )B!d,HKt;
boolean breakWhile = false; ir:d'g1k
%>WbmpIyc
zTD@
while(!bStop) *8ExRQZ$
{ 8z<r.joxC
write_nPos(); eV6o3u:9
Utility.sleep(500); '+*-s7o{
breakWhile = true; n^hocGH*
#)`A7 $/,
(shK
for(int i=0;i<nStartPos.length;i++) &kQ!KA28
{ ArI]`h'W
if(!fileSplitterFetch.bDownOver) ]$M<]w,IJ2
{ cgj.e
breakWhile = false; fA^7^0![
break; 4Z)DDz-}V
} cX At:m
} \h3e-)
if(breakWhile) Y'Z+, CNf
break; mEQ!-p
mYNEz @
d `j?7Z
//count++; ,vG<*|pn
//if(count>4) @ERu>nSP
// siteStop(); 3AlqBXE"Z<
} EX?h0Uy
~4)Y#IxL
PM4>ThQ
System.err.println("文件下载结束！"); "A]Y~iQ
} 9b6!CNe!
catch(Exception e){e.printStackTrace ();} 2W3W/> 2h
} P 4;{jG
o&^NwgRCF
>$F:*lO
//获得文件长度 wk02[
public long getFileSize() #@Ujx_F
{ MB*u-N0v
int nFileLength = -1; w{'2q^>6*
try{ 4&N$:j<
URL url = new URL(siteInfoBean.getSSiteURL()); aed+C:N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q[s2}Z!N;
httpConnection.setRequestProperty("User-Agent","NetFox"); 9NWloK6bT
\8"QvC]
V_;9TC
int responseCode=httpConnection.getResponseCode(); 8Z:Ezg3^
if(responseCode>=400) 7Qh_8M
{ H4skvIl
processErrorCode(responseCode); <lOaor c
return -2; //-2 represent access is error S!7g)
} f[qPG&
{Bvm'lq`
e d;"bb
String sHeader; :l~EE!
`{G?>z Fp
/{DaPqRa
for(int i=1;;i++) ,U%=rfB~
{ M5Wl3tZL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b5Q8pWZg,
//Utility.log(in.readLine()); Z}[xQ5
sHeader=httpConnection.getHeaderFieldKey(i); [EGx
if(sHeader!=null) wsfysat$
{ gPUo25@pn*
if(sHeader.equals("Content-Length")) _[1^s$
{ gUGOHd(A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XTj73 MWY
break; ;\s~%~\
} }Z-I2 =]
} @,YlmX}
else cno;>[$
break; O!];_q/
} L *{QjH
} c `ud;lI
catch(IOException e){e.printStackTrace ();} y.fs,!|%@
catch(Exception e){e.printStackTrace ();} A^cU$V%?W
3"vRK5Bf
&GU@8
Utility.log(nFileLength); 8;8YA1@w
`A"Q3sf%
:p&IX"Hh
return nFileLength; UnjNR[=
} p6[#f96^u
qM*S*,s
lJ'trYaq7
//保存下载信息（文件指针位置） t]r7cA
private void write_nPos() .}~$1QKS
{ |f3U%2@
try{ W[GQ[h
output = new DataOutputStream(new FileOutputStream(tmpFile)); 77^ "xsa
output.writeInt(nStartPos.length); wH#-mu#Yl<
for(int i=0;i<nStartPos.length;i++) -HN%B?}. x
{ k%^<}s@
// output.writeLong(nPos); & L3UlL
output.writeLong(fileSplitterFetch.nStartPos); )ZN(2z
output.writeLong(fileSplitterFetch.nEndPos); %awVVt{aG
} [='p!7z
output.close(); .`mtA`N
} /4^G34
catch(IOException e){e.printStackTrace ();} o|+E+l9\
catch(Exception e){e.printStackTrace ();} rWqkdi1
} 6QW<RXom
||`qIElAW,
q`cEA<~S
//读取保存的下载信息（文件指针位置） [h^f%
private void read_nPos() (GnVwJ<v9V
{ 90?,-6
try{ m,=)qex
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *$JB`=Q
int nCount = input.readInt(); |GuKU!
nStartPos = new long[nCount]; )&XnM69~b
nEndPos = new long[nCount]; U%h7h`=F?
for(int i=0;i<nStartPos.length;i++) 0n\^$WY
{ >H)^6sJ;%b
nStartPos = input.readLong(); m';#R9\Fz
nEndPos = input.readLong(); .r7D)xNa@
} 9^(HXH_f
input.close(); #>@<n3rq
} m**0rpA
catch(IOException e){e.printStackTrace ();} &3WkH W
catch(Exception e){e.printStackTrace ();} DL %S(l
} uXjoGcW
n}=rj7
g'KzdG`O0
private void processErrorCode(int nErrorCode) Ft)t`E'%j
{ {ms,q_Zr
System.err.println("Error Code : " + nErrorCode); nt drXg
} Qk+=znJ
n?zbUA#
t8t}7XD
//停止文件下载 aB=vu=hF
public void siteStop() ;R/k2^uF
{ N 9c8c
bStop = true; S&5Q~}{,
for(int i=0;i<nStartPos.length;i++) UaH26fWs
fileSplitterFetch.splitterStop(); /&*m1EN#o
P{"WlJ
ub[""M?
} .=>\Qq%
} m5X3{[a:
//负责部分文件的抓取 o G(0i
**FileSplitterFetch.java aUKh})B
*/ ?H y%ULk
package NetFox; o9_(DJ<{
M4zX*&w.T
F9Ifw><XM
import java.io.*; xN e_qO
import java.net.*; #S@UTJa
=$^Wkau
{z.[tvE8h
public class FileSplitterFetch extends Thread { >r;ABz/
>(IITt
l5{(z;xM
String sURL; //File URL /d{glOk
long nStartPos; //File Snippet Start Position tn"Y9 k|
long nEndPos; //File Snippet End Position 4$0jz'
int nThreadID; //Thread's ID "}S9`-Wd|
boolean bDownOver = false; //Downing is over @`w'
boolean bStop = false; //Stop identical A6{t%k~F
FileAccessI fileAccessI = null; //File Access interface >&$$(Bp
Rf)'HT
RY\{=f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e*Uz#w:
{ P]!LN\[
this.sURL = sURL; GCcwEl!K^
this.nStartPos = nStart; S 23S.]r
this.nEndPos = nEnd; >Sc$R0
nThreadID = id; wm); aWP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (Wm/$P;
} 2"pE&QNd
t` }20=I+
:NwMb^>
public void run() X% Spv/8{
{ hKk\Y{wv'
while(nStartPos < nEndPos && !bStop) n.2E8m/
{ i1b4 J
qT4I Y$h
8CHb~m@^$
try{ #JJp:S~`
URL url = new URL(sURL); pRQfx^On
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *kX3sG$8
httpConnection.setRequestProperty("User-Agent","NetFox"); *=-__|t
String sProperty = "bytes="+nStartPos+"-"; OYqYI!N/
httpConnection.setRequestProperty("RANGE",sProperty); v$gMLu=
Utility.log(sProperty); R$!;J?SS
,cGwtt(
Hj5WJ{p.
InputStream input = httpConnection.getInputStream(); jSeA%Te
//logResponseHead(httpConnection); -V;0_Nx7p
4b3F9
Pe+ 8~0o=R
byte[] b = new byte[1024]; ]MqH13`)A
int nRead; Q|j@#@O1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jV,(P$ 5;
{ <FUqD0sQ
nStartPos += fileAccessI.write(b,0,nRead); D,}'E0
//if(nThreadID == 1) f>\bUmk(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f_re"d 3u
} @yU!sE:
e'/
t6<sNzF&
Utility.log("Thread " + nThreadID + " is over!"); :f?,]|]+-
bDownOver = true; 4pfix1F g
//nPos = fileAccessI.write (b,0,nRead); +!L_E6pyXE
} 0p:ClM2O
catch(Exception e){e.printStackTrace ();} 66^1&D"
} |"Xi%CQ2
} =M/UHOY
RS||KA])J
!_XU^A>
//打印回应的头信息 r?5@Etpg
public void logResponseHead(HttpURLConnection con) I9:G9
{ 0TuOY%+
for(int i=1;;i++) XvA0nEi
{ g9([3pV,
String header=con.getHeaderFieldKey(i); ga{25q}"
if(header!=null) ;G4HMtL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d}wa[WRv
Utility.log(header+" : "+con.getHeaderField(header)); 2vh!pez_
else s_GK;;
break; ~*' 8=D?)
} 9h3~;Q
} 5|6z1{g8
_pH6uuB
8H3!; ]
public void splitterStop() *&hXJJ[+
{ +]S;U&vQ
bStop = true; shDt&_n
} ^7~SS2t!
8JtI&aH-L
Wy^[4|6
} < o'7{
8)-t91hkL
"#\bQf}
/* 2W"cTm
**FileAccess.java O&?CoA?
*//文件访问(定位，写) St3(1mApl
package NetFox; M[ ~2,M&H
import java.io.*; 0IPhVG~#
k9_VhR|!
tZNad
public class FileAccessI implements Serializable{ >Rki[SNb-b
o. V0iS]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hyvV%z Z
RandomAccessFile oSavedFile; g]iy-,e
long nPos; qh(-shZ4Du
[BZ(p
L yA(.
public FileAccessI() throws IOException SbPjU50
{ vU$O{|J
this("",0); X,!OWz:[
} L1Cn
@Pb 1QLiz
0ZID @^
public FileAccessI(String sName,long nPos) throws IOException Ji}IV
{ U70@}5!
oSavedFile = new RandomAccessFile(sName,"rw"); $NGtxZp
this.nPos = nPos; *Xtc`XH
oSavedFile.seek(nPos); ^cmP
} cdtzf:#q
GaK_9Eg-2
FUqhSW
public synchronized int write(byte[] b,int nStart,int nLen) PcSoG\-G<
{ v/TlXxfil
int n = -1; ^`>Ysc(@&
try{ G4exk5
oSavedFile.write(b,nStart,nLen); a@=36gx)
n = nLen; xZ'`_x9l
} jVFRqT%
catch(IOException e) _F|_C5A
{ w6In{uO-Z
e.printStackTrace (); u FYQ^
} WPp\sIP
zc,9Qfn
Z=t#*"J
return n; FiU;>t<)
} uuK]<h*
;pNbKf:
8.%a"sxr
} g d}TTe
K"6+X|yxE
i!}nGJGg
/* y[@j0xlO
**SiteInfoBean.java `~+a=Q
*/ `J,~hK
package NetFox; w4MMo
L"du"-
&{4Mo,x
public class SiteInfoBean { {6y.%ysU
sd@gEp)L
:8|3V~%m
private String sSiteURL; //Site's URL RJsG]`
private String sFilePath; //Saved File's Path GxBPEIim
private String sFileName; //Saved File's Name qH$rvD!]
private int nSplitter; //Count of Splited Downloading File U W)&Eky
|e;z"-3
M^Ay,jK!
public SiteInfoBean() jc~*#\N
{//nSplitter的缺省值为5 2c`=S5
//default value of nSplitter is 5 VJtTbt;>
this("","","",5); )I-?zyL
} 5b4V/d* '
@C [|'[xQ
=?*"V-l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eh7r'DmAR
{ +P)[|y +e
sSiteURL= sURL; `1}?{ud
sFilePath = sPath; ;OCI.S8
sFileName = sName; l=?y=2+
this.nSplitter = nSpiltter; ;Owu:}
{s'_zSz
Y^m=_*1g5
} !E#.WX
U\ E{-7
Ollv _o3
public String getSSiteURL() 8=o5;]Cg
{ 3$yL+%i
return sSiteURL; f4y;K>u7p
} T9<nD"=:
QuRg(K%:
v.v%k2;
public void setSSiteURL(String value) jz7ltoP
{ i[^lJ)[>N
sSiteURL = value; v oS"X
} >!F,y3"5S
zXU{p\;)\
ZBq*<VtV
public String getSFilePath() +5|nCp6||j
{ v/+}FS=
return sFilePath; "?&bh@P&
} :k/U7 2
]3u'Qv}o
Y4!q 1]TGX
public void setSFilePath(String value) UKQ&TV}0
{ CWsv#XOg]
sFilePath = value; n(xlad
} SWd[iD
LVl0:!>~
&B0&183
public String getSFileName() Y]Vc}-a(h
{ Cwf$`?|W
return sFileName; mg/kyua^
} <+,0G`
fQ4$@
+p6\R;_E
public void setSFileName(String value) nJH%pBc
{ Jxw:Jk ~
sFileName = value; Cbvl( (
} 8%f! X51
Qnx92
F+S#m3X
public int getNSplitter() 3DvkoV
{ EZRZ)h
return nSplitter; 1)Bi>X
} E9-'!I!
(k.7q~:
=8_TOvSJ4p
public void setNSplitter(int nCount) Vn;]''_
{ 7Q}@L1A9F,
nSplitter = nCount; CoXL;\
} j&GKpt
} 1A.\Ao
.cog9H'
e91d~
/* ~kT{O!x}4
**Utility.java cs;Gk:
*/ Vs"Q-?
package NetFox; \>7-<7+I6
#eyx
|JQKxvjT
public class Utility { FuBRb(I
{z_pL^S'52
Te#[+B?
public Utility() JdEb_c3S
{ ! NEq|Y
{v 0(0
"ZW*O{
} t[,\TM^h}0
<sOB j'
//线程睡眠 -;z\BW5y
public static void sleep(int nSecond) f|5|n>*
{ <qx-%6
try{ WfZ#:G9
Thread.sleep(nSecond); ^o:5B%}#[
} 8!Kfe
catch(Exception e) bNgcZ V.
{ TA7w:<
e.printStackTrace (); &pl;U\dc*a
} WU_Q 7%+QS
} A???s,F_
$hh=-#J8
//日志 &LYZQ?|
public static void log(String sMsg) VEm[F/'
{ `#F>?g$2
System.err.println(sMsg); "&F/'';0}E
} r$zXb9a|<
s]OXB {M
m%puD9
public static void log(int sMsg) '"a8<7
{ 7\lc aC@
System.err.println(sMsg); 8nM]G4H.f
} T^t`Hp
} X3vrD{uNU
qm@hD>W+
mi?Fy0\
/* d1N&J`R\1
**TestMethod.java ;$]R#1i44
*/ Emo]I[<&q
package NetFox; B}.ia_&DLR
^m\n[<x^
hQO~9mQ+!
public class TestMethod { x($1pAE
@VFg XN
IU/*YI%W
public TestMethod() 0vEa]ljS
{ ///xx/weblogic60b2_win.exe 89l}6p/L
try{ 8dfx _kY`/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yL1\V7GI{[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @M-bE=
SiteFileFetch fileFetch = new SiteFileFetch(bean); MwZ`NH|n3"
fileFetch.start(); BDA\9m^3
} +%^D)
catch(Exception e){e.printStackTrace ();} .u)YZN0\
~2H)#`\ac8
y g7z?AZ
} 4Y'qoM;
3ul
rB\UNXy
public static void main(String[] args) {k>m5L
{ Wo%&,>]<H
new TestMethod(); : f Wh7X3
} ^,50]uX_
} J_tJj8
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