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)); ak&v/%N
} ;c}];ZU3G
for(int i=0;i<nEndPos.length-1;i++) lvffQ_t
{ <GEn9;\
nEndPos = nStartPos[i+1]; BW[K/l~"$:
} K.Ir+SB
nEndPos[nEndPos.length-1] = nFileLength; &Gl&m@-j
} _FgeE`X
} djM=QafB:C
p:))ne:7
|+''d
//启动子线程 HB:i0m2fJW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !9NAm?Fw
for(int i=0;i<nStartPos.length;i++) F*H}5yBp_:
{ 2e=Hjf )
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $4]PN2d&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gd*?kXpt
nStartPos,nEndPos,i); c^%k1pae(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +UtK2<^:o
fileSplitterFetch.start(); egvWPht'_
} <hdCO< 0(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `$HO`d@0*R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %cL:*D4oz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", TMBdneS-s
nEndPos = " + nFileLength); /0(KKZ)
// fileSplitterFetch[nPos.length-1].start(); RB!E>]
nm.d.A/]Z
%{"STbO#>
//等待子线程结束 hW&UG#PY>
//int count = 0; hd' n"
//是否结束while循环 N0f}q1S<-A
boolean breakWhile = false; m~A/.t%=
t=#)3C`Q}
I 3PnyNZ
while(!bStop) E83nEUs
{ Cz%ih#^b
write_nPos(); 71InYIed
Utility.sleep(500); YoA$Gw2
breakWhile = true; O&uOm:/(
Pe.D[]S
We2=|AB
for(int i=0;i<nStartPos.length;i++) I(SE)%!%S
{ |)?T([
if(!fileSplitterFetch.bDownOver) U$}]zaB
{ w.\:I[
breakWhile = false; th{h)( +H
break; vP!gLN]TV
} ;d4_l:9p
} ;f\0GsA#
if(breakWhile) Nx__zC^r
break; 5ZLH=8L
'(}BfDP
VTU-'q
//count++; Rx.0P6s
//if(count>4) \kx9V|A'
// siteStop(); =v8q
} t!tBN
;uy/Vc5,Y
w# ['{GL
System.err.println("文件下载结束！"); Y9N:%[ :>W
} (;N_lF0
catch(Exception e){e.printStackTrace ();} 0ro+FJ r
} a/1{tDA
I5mS!m/X
-oj@ c OZ
//获得文件长度 ;_!;D#:
public long getFileSize() ?a% u=G
{ ?(z3/"g]
int nFileLength = -1; |NqQKot1
try{ lz>hP
URL url = new URL(siteInfoBean.getSSiteURL()); "F&uk~ b$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 827N?pU$)
httpConnection.setRequestProperty("User-Agent","NetFox"); |8"HTBb\CW
WW.=>]7;
2rk_ ssvs
int responseCode=httpConnection.getResponseCode(); [(hENX}o:
if(responseCode>=400) (Jm_2CN7X
{ (`&g
processErrorCode(responseCode); \)bwdNWI
return -2; //-2 represent access is error #oaX<,
} 7K~=QEc
g?ft;kR6S
uv$y"1'g
String sHeader; (+@H !>r$$
4s~o
01J.XfCd6
for(int i=1;;i++) H:`r!5&Qb5
{ JW$#~"@r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); BmZd,}{
//Utility.log(in.readLine()); )9$Xfq/
sHeader=httpConnection.getHeaderFieldKey(i); ;]gph)2cd
if(sHeader!=null) @S{,g;8
{ y(HR1vQ;Z
if(sHeader.equals("Content-Length")) w*?JW
{ F 1BPzRo`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $ _zdjzT
break; +#O?sI#
} ppxu\a
} W\"cp[b
else <B)lV'!Bd
break; QS[%`-dR2
} n%Fa;!S
} ,,?t>|3
catch(IOException e){e.printStackTrace ();} a}yJ$6xi
catch(Exception e){e.printStackTrace ();} 'uh6?2)wG
2axH8ONMu
c7'Pzb)'
Utility.log(nFileLength); &{>~|^
/)|*Vzu
GB0] |z5
return nFileLength; OHB!ec6W
} &{$\]sv
=T1i(M#
tw;`H( UZ^
//保存下载信息（文件指针位置） {2,V3*NF
private void write_nPos() ^'}Td~(
{ h' 16"j>
try{ >y1/*)O9~
output = new DataOutputStream(new FileOutputStream(tmpFile)); nD!^0?
output.writeInt(nStartPos.length); SkY|.w.
for(int i=0;i<nStartPos.length;i++) %FwLFo^v
{ 1iUy*p65:
// output.writeLong(nPos); 6d_l[N
output.writeLong(fileSplitterFetch.nStartPos); Cu}Rq!9i
output.writeLong(fileSplitterFetch.nEndPos); `.n[G~*w~1
} SQ@@79A
output.close(); +!X^E9ra
} sGV%O=9?2
catch(IOException e){e.printStackTrace ();} wJ{M&n1H
catch(Exception e){e.printStackTrace ();} :g Ze>
} Ih.o;8PpK
aFLm,
JV@>dK8
//读取保存的下载信息（文件指针位置） ce@(Ct
private void read_nPos() q*2ljcb55
{ il*bsnwpZv
try{ )J0'We
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IuPwFf)
int nCount = input.readInt(); DJeG
nStartPos = new long[nCount]; b.$Gc!g
nEndPos = new long[nCount]; =!7yX;|
for(int i=0;i<nStartPos.length;i++) K%S k{'
{ Zf|f $1-
nStartPos = input.readLong(); 8Y:bvs.j
nEndPos = input.readLong(); C6GYhG]
} SwQb"
input.close(); 0%vXPlfnY
} $"sf%{~
catch(IOException e){e.printStackTrace ();} BONM:(1
catch(Exception e){e.printStackTrace ();} 55Jk "V#8
} Q|:\
WFtxEIrl3j
GX\/2P7CZ
private void processErrorCode(int nErrorCode) =\tg$
{ % nJ'r?+h
System.err.println("Error Code : " + nErrorCode); C0'Tua'
} GMFp,Df
++xEMP)
>zXw4=J
//停止文件下载 9^`G `D
public void siteStop() ndN8eh:OR
{ P\SE_*&
bStop = true; 1h|JKu0
for(int i=0;i<nStartPos.length;i++) 8%Pjx7'<
fileSplitterFetch.splitterStop(); zL1H[}[z+
2OEOb,`
#qHo+M$"
} *Bc=gl$
} RzXxnx)]q
//负责部分文件的抓取 R:=i/P/
**FileSplitterFetch.java o: TO[
*/ nsYS0
package NetFox; &AC-?R|Dp
;[&g`%-H<
a Z ^SK|E
import java.io.*; 7|\[ipVX:3
import java.net.*; `XQM)A
,_p_p^Ar\4
]ZZ7j
public class FileSplitterFetch extends Thread { b bX2D/
\S3C"P%w
/8lGP!z
String sURL; //File URL amOBUD5Ld`
long nStartPos; //File Snippet Start Position 9J*m!-hOY
long nEndPos; //File Snippet End Position P$\(Bd\76
int nThreadID; //Thread's ID W%) foJ
boolean bDownOver = false; //Downing is over SxNs
boolean bStop = false; //Stop identical ^qGH77#z
FileAccessI fileAccessI = null; //File Access interface #|)GarDG
C^]bXIb
Bx;bc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dX` _Y
{ Qr$uFh/y
this.sURL = sURL; {V,rWg
this.nStartPos = nStart; HX?5O$<<N
this.nEndPos = nEnd; EPW Iu)A
nThreadID = id; ,:j^EDCsaJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 oljl&tuQy
} + ,0RrD )
}fUV*U:3
7'd_]e-.
public void run() TAIcp*)ZM
{ IYb@@Jzo
while(nStartPos < nEndPos && !bStop) >(p "!
{ ~%m-}Sxc
2 ES .)pQ
d2Bn`VI
try{ 1P@&xcvS\
URL url = new URL(sURL); ="z\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f?[IwA`
httpConnection.setRequestProperty("User-Agent","NetFox"); b2duC
String sProperty = "bytes="+nStartPos+"-"; e%o6s+"
httpConnection.setRequestProperty("RANGE",sProperty); >DpnIWn
Utility.log(sProperty); rQ LNo,
"EDn;l-Q
p~En~?<
InputStream input = httpConnection.getInputStream(); 3T%WfS+
//logResponseHead(httpConnection); aa8WRf
}r9f}yX9Q
3;@t{rIin
byte[] b = new byte[1024]; _z#zF[%
int nRead; 77.5 _
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RV.*_FG
{ x=gZ7$?A
nStartPos += fileAccessI.write(b,0,nRead); A7 E*w
//if(nThreadID == 1) /!uxP~2U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !zVuO*+
} Ay22-/C|@
7?dB&m6W
n@Y`g{{e~
Utility.log("Thread " + nThreadID + " is over!"); JY~s-jxa
bDownOver = true; /)e&4.6
//nPos = fileAccessI.write (b,0,nRead); x?VX,9;j
} &S]\)&Yt
catch(Exception e){e.printStackTrace ();} -6aGcPq
} 5a&[NN
} fYl$$.
A!x_R {,yH
NyFa2Ihd
//打印回应的头信息 pg;agtI
public void logResponseHead(HttpURLConnection con) S2@[F\|r
{ 120<(#
for(int i=1;;i++) D9 OS,U/l
{ (G*--+Gn
String header=con.getHeaderFieldKey(i); gQCkoQi:j
if(header!=null) h1:uTrtA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,yNPD}@v>
Utility.log(header+" : "+con.getHeaderField(header)); .yd{7Te
else 80x %wCY`
break; 3 8m5&5)1F
} FDkRfhK
} nxA Y]Q
Z;P[)q
/#GX4&z
public void splitterStop() JnlM0jc]`
{ =;9Wh!{
bStop = true; Y7zg
} s0~a5Ti3
r=~yUT
1>[3(o3t
} *1$rg?yGf
`_N8AA
;^^u_SuH
/* tz4MT_f
**FileAccess.java VrD?[&2pE
*//文件访问(定位，写) 7%c9 nY
package NetFox; Ks(+['*S
import java.io.*; . Zrt/;
pLE|#58I
@0;9.jml,
public class FileAccessI implements Serializable{ ]8NNxaE3(
!k)}p_e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;XMbjWc
RandomAccessFile oSavedFile; Zrr3='^s
long nPos; mqrP0/sN
Q.*qU,4);
f<= #WV
public FileAccessI() throws IOException <x,u!}5J
{ F42r]k
this("",0); H[wJ; l
} Py^F},?J
+y!dU{L^
iW(HOsA
public FileAccessI(String sName,long nPos) throws IOException sU^2I v\%
{ Ol`/r@s
oSavedFile = new RandomAccessFile(sName,"rw"); N6S0(%
this.nPos = nPos; s4<[f%^
oSavedFile.seek(nPos); 9x0B9&
} (\{9W
r /63
mT <4@RrB
public synchronized int write(byte[] b,int nStart,int nLen) YAv-5
{ E{[c8l2B
int n = -1; mk2T
try{ f ?_YdVZ
oSavedFile.write(b,nStart,nLen); ^o+2:G5z}
n = nLen; bHH{bv~Z
} *6sB$E_y
catch(IOException e) " ;_bB"q*
{ !@{_Qt1
e.printStackTrace (); 1&\_|2
} GNS5v-"H
[u;]J*
kj~)#KDN
return n; -==@7*x!Z
} ~ ' 81
BG_m}3j
~aQ>DpSEf
} .Qg!_C
kSv?p1\@&P
$qYtN`b,
/* d/!sHr69
**SiteInfoBean.java "IA[;+_"
*/ T8h.!Vef
package NetFox; sesr`,m.,
B$1nq#@
1k6f|Al-
public class SiteInfoBean { Wp/!;
*[*LtyCQt4
5V!L~#
private String sSiteURL; //Site's URL TS^(<+'
private String sFilePath; //Saved File's Path mf=,6fx28
private String sFileName; //Saved File's Name =K I4
private int nSplitter; //Count of Splited Downloading File JryDbGc8
k!H;(B"s-
/6B!&b2f
public SiteInfoBean() @a#qq`b;
{//nSplitter的缺省值为5 VQ5T$,&
//default value of nSplitter is 5 v|t_kNX;v*
this("","","",5); ge)g?IP4
} /Mb?dVwA
=B4U~|k
{(]B{n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s Z(LT'}
{ 2hdi)C,7Y
sSiteURL= sURL; O Ul+es
sFilePath = sPath; M,"4r^%k
sFileName = sName; _m;0%]+
this.nSplitter = nSpiltter; EKZ40z`
?vPwI
EgM.wQHR]
} +Gqh
yx"xbCc#
)28Jz6.I
public String getSSiteURL() osyY+)G'sV
{ ,LKY?=T$z
return sSiteURL; YNA %/
} {\[u2{
b2u_1P\
"(5A5>
public void setSSiteURL(String value) *q_ .y\D
{ FKY|xG9
sSiteURL = value; Yxz(g]
} fp|!LU
9-[g/qrF
o)F^0t
public String getSFilePath() *X+T>SKL
{ $J"}7+
return sFilePath; jo{[*]Oa
} ~j}di^<{
dy N`9
\2 &)b
public void setSFilePath(String value) {c`kC]9
{ }C!N$8d,
sFilePath = value; lfG]^id'
} tX$%*Uy
#X'!wr|-
KGdL1~
public String getSFileName() @;2,TY>Di
{ 8`XpcK-0
return sFileName; zRN_`U
} 0^nnR7
Z7% |'E R
W=41jw
public void setSFileName(String value) \_}Y4
{ wG[X*/v
sFileName = value; EL$l . v
} =Y#)c]`
%$|=_K)Ks
~f0Bu:A)
public int getNSplitter() NF&R}7L
{ gd^1c}UZX
return nSplitter; )D_#
} ,!_$A}@0 ^
{%X /w'|
RX}6H<5R
public void setNSplitter(int nCount) VeeQmR?u-
{ Tu95qL~^
nSplitter = nCount; \72(d
} fvK):eCo
} ?RJ )u
(Em^qN
uq~$HXdc
/* Cp=DdmR
**Utility.java >Pj ?IE6
*/ v?BX 4FO
package NetFox; hZf0q 2
LnP={s
0*S]m5#;
public class Utility { Gh}sk-Xk=
IOmQ1X7,
(b%&DyOt
public Utility() 8sjAr.iT.
{ F+ qRC_C>O
1^^<6e
Wcd;B7OH
} 4^\5]d!
8gWifx #N
//线程睡眠 CIAHsbn.A
public static void sleep(int nSecond) Lb;:<
{ SVWtKc<
try{ 4%>iIPXi.(
Thread.sleep(nSecond); Uu ~BErEC
} SE/GT:}
catch(Exception e) *-"DZ
{ Wm\HZ9PN
e.printStackTrace (); unu%\f>^4
} Tl"GOpH\]
} m[7@l
}@%A@A{R
//日志 ,paD/
public static void log(String sMsg) L]I ;{Y
{ !j[Oyr|
System.err.println(sMsg); h}r64<Y2{
} ?4v&TB@
Jk=E"I6
:E'uV"j%
public static void log(int sMsg) N GP}Z4
{ 9nF;$HB
System.err.println(sMsg); W@U<GF1
} w:%3]2c
} `%_yRJd|;
e<o{3*%p)
OhMnG@@
/* '&?cW#J?
**TestMethod.java wh8h1I
*/ :4RD.l
package NetFox; NT+%u-
|35"V3bs
OXc!^2^
public class TestMethod { w/+e
1}nrVn[B9
~k>H4hV3
public TestMethod() ?IgM=@
{ ///xx/weblogic60b2_win.exe %GS^=Qr
try{ j_L1KB*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^y:!=nX^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1t7vP;
SiteFileFetch fileFetch = new SiteFileFetch(bean); l]tda(
fileFetch.start(); CqHCJ '
} k$]-fQM
catch(Exception e){e.printStackTrace ();} }4G/x;D
W$&{jr-p
#nG?}*#
} =(\ /+ 0-[
2MS-e}mi
vzDoF0Ts*p
public static void main(String[] args) AA$+ayzx9{
{ nGb%mlb
new TestMethod(); h# R;'9*V
} j$v2_q
} $&D$Uc`U>
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