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)); *]~ug%a
} tVd\r"0k
for(int i=0;i<nEndPos.length-1;i++) D8N}*4S
{ 5Z}]d@
nEndPos = nStartPos[i+1]; SCE5|3j
} -}0S%|#m
nEndPos[nEndPos.length-1] = nFileLength; ?ix--?jl
} -frmvNJ F
} ARAC'F0
;>_\oZGj_
5<bc>A-
//启动子线程 AEx I!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S?nk9T+
for(int i=0;i<nStartPos.length;i++) %o9@[o .]
{ `E>HpRcxD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aO('X3?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZB GLwe
nStartPos,nEndPos,i); 4k_&Q?1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Mit,X
fileSplitterFetch.start(); SV16]Vc
} 4>nY't;0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,<F=\G_f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %"PG/avo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^pZ1uN!b
nEndPos = " + nFileLength); t m?[0@<s
// fileSplitterFetch[nPos.length-1].start(); zF6R\w
%`%oupqm+
!"/]<OQ
//等待子线程结束 3^ ~M7=k
//int count = 0; K[0.4+
//是否结束while循环 A<l8CWv[
boolean breakWhile = false; jZeY^T)f"
tGnBx)J|
#pu6^NTK
while(!bStop) !!Z#'Wq
{ 4s nL((
write_nPos(); zb.^ _A
Utility.sleep(500); ;EbGW&T
breakWhile = true; 3Yf&F([t
Ig75bZz
occ^bq
for(int i=0;i<nStartPos.length;i++) T%~w~stW
{ 01N"
if(!fileSplitterFetch.bDownOver) w naP?|/
{ {'VP_ZS1v
breakWhile = false; r(xh5{^x
break; O6Bs!0,
} t-Rfy`I3
} D7|[:``
if(breakWhile) (n+2z"/
break; OJiW@Z_\
<<`*o[^L
:;W[@DeO[
//count++; B.CUk.
//if(count>4) xF: O6KL
// siteStop(); &<6E*qM
} *,<A[XP
vdw5T&Q{{C
z<aBGG
System.err.println("文件下载结束！"); tJ[yx_mf
} l+!!S"=8)~
catch(Exception e){e.printStackTrace ();} KBJw7rra
} pSp/Qpb-B
DhZuQpH
j#QJ5(#
//获得文件长度 P8!ON=
public long getFileSize() Ix@rn
{ /5Aum?~
int nFileLength = -1; eygmhaE
try{ +\g/KbV7
URL url = new URL(siteInfoBean.getSSiteURL()); jGpSECs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C(zgBk
httpConnection.setRequestProperty("User-Agent","NetFox"); |f), dC
|U{9Yy6p
F: %-x=q
int responseCode=httpConnection.getResponseCode(); ly"Jl8/<
if(responseCode>=400) WLl_;BgN
{ q1ybJii
processErrorCode(responseCode); "%fh`4y3\
return -2; //-2 represent access is error 0/K?'&$yvb
} u3 k%
]j> W9n?
hkV;(Fr&z
String sHeader; 0WT]fY?IS
a(AKVk\
]D?//
for(int i=1;;i++) ta"uxL\gge
{ G165grGFd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~hK7(K
//Utility.log(in.readLine()); F.5'5%
sHeader=httpConnection.getHeaderFieldKey(i); Z(DCR/U=(>
if(sHeader!=null) d: D`rpcC
{ oV"d%ks
if(sHeader.equals("Content-Length")) xxjg)rVuy
{ eewhT^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {gh41G;n
break; 2gM=vaiH=
} MzjV>.
} $ N`V%<W
else 9U[Gh97Sf
break; ldp x,
} ql"&E{u?
} gc(Gc vdB\
catch(IOException e){e.printStackTrace ();} AGaM &x=
catch(Exception e){e.printStackTrace ();} ^b|Z<oF
3m3ljy
mGx!{v~i&
Utility.log(nFileLength); \7b-w81M-
DUH\/<^g
ZK:dhwer
return nFileLength; W0e+yIaR
} $VEG1]/svp
?LJ$:u
fP3e{dVf
//保存下载信息（文件指针位置） cs[_TJo
private void write_nPos() EWOS6Yg7
{ p7 s#j
try{ kc*zP=
output = new DataOutputStream(new FileOutputStream(tmpFile)); )Z6bMAb0'N
output.writeInt(nStartPos.length); ZEY="pf
for(int i=0;i<nStartPos.length;i++) \8j5b+
{ q5 eyle6
// output.writeLong(nPos); #I> c$dd
output.writeLong(fileSplitterFetch.nStartPos); YywiY).]@
output.writeLong(fileSplitterFetch.nEndPos); WMy97*L<
} +*u'vt?
output.close(); 590.mCm
} 3OnIAk3
catch(IOException e){e.printStackTrace ();} <JtH/oN
catch(Exception e){e.printStackTrace ();} Bmx+QO
} Zop3[-
x)evjX=q
A8,9^cQ]
//读取保存的下载信息（文件指针位置） M)v\7a
private void read_nPos() ++O L&n
{ OJ#ehw<
try{ j,<3[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hxG=g6:G
int nCount = input.readInt(); V|6PKED
nStartPos = new long[nCount]; +'fy%/
nEndPos = new long[nCount]; wVegr
for(int i=0;i<nStartPos.length;i++) D#%aow'(7
{ JFAmND;+
nStartPos = input.readLong(); 5\\#kjjx
nEndPos = input.readLong(); mjgwU8'![
} LV4\zd6
input.close(); k+-IuO
} mCM7FFl I
catch(IOException e){e.printStackTrace ();} b1+6I_u.
catch(Exception e){e.printStackTrace ();} q/T(s
} ` =ocr8c
v[$-)vs*ag
DlC\sm
private void processErrorCode(int nErrorCode) Zl,c+/
{ }"} z7Xb0
System.err.println("Error Code : " + nErrorCode); So?.V4aD_
} 'u9,L FO
8H2zMIB
3k YVk
//停止文件下载 [tN^)c`s/
public void siteStop() 0*e)_l!
{ oJ\)-qSf
bStop = true; kg,t[Jl
for(int i=0;i<nStartPos.length;i++) >L5fc".
fileSplitterFetch.splitterStop(); z+@CzHCN
yH`4sd
* SAYli+@
} Ufx^@%v
} 48}L!m @
//负责部分文件的抓取 cb36~{
**FileSplitterFetch.java P:~Xaz\F
*/ XOOWrK7O
package NetFox; NxOiT#YH
euxkw]`h6
hbZ]DRg
import java.io.*; Qu 7#^%=
import java.net.*; )gX7qQ
6snDv4
0^%\! Xxq
public class FileSplitterFetch extends Thread { 3K{XT),
A%Ov.~&\G
=J@M,mbHg
String sURL; //File URL bIvF5d>9#K
long nStartPos; //File Snippet Start Position [_$r-FA
long nEndPos; //File Snippet End Position :eK(9o
int nThreadID; //Thread's ID l ~bjNhk
boolean bDownOver = false; //Downing is over )7X+T'?%
boolean bStop = false; //Stop identical B: '}SA{
FileAccessI fileAccessI = null; //File Access interface ~Onj|w7
72i]`
-|1H-[Y(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w@K4u{|
{ W|~Jl7hs8Q
this.sURL = sURL; #=}dv8
this.nStartPos = nStart; =O~ J
this.nEndPos = nEnd; It5U=PU
nThreadID = id; M lv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O~p@87aq
} A~2U9f+\
os:/-A_m
jwP}{mi*
public void run() trl:\m
{ $q"/q*ys
while(nStartPos < nEndPos && !bStop) B #[URZ9S
{ ~RdD6V
'7'*+sgi$
Mx-? &
try{ fG *1A\t]
URL url = new URL(sURL); P4\{be>e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "PFczoRZ
httpConnection.setRequestProperty("User-Agent","NetFox"); E?VPCx
String sProperty = "bytes="+nStartPos+"-"; 0r4,27w
httpConnection.setRequestProperty("RANGE",sProperty); &1=Je$,
Utility.log(sProperty); k!&G;6O-
|igr3p5Fw
PIZnzZ@Z;
InputStream input = httpConnection.getInputStream(); "7]YvZYu0
//logResponseHead(httpConnection); TO(2n8'fdO
MC 8t"SB
5} v(Ks>
byte[] b = new byte[1024]; 'ycr/E&m{
int nRead; dkHye>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?&ow:OH+
{ G,{=sFX
nStartPos += fileAccessI.write(b,0,nRead); OpNTyKbaD
//if(nThreadID == 1) S":55YQev!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7o+JQ&fF;
} ;~A-32;Y4
Fwu:x.(
iRbTH}4i
Utility.log("Thread " + nThreadID + " is over!"); fbl8:c)I
bDownOver = true; qI]PM9
//nPos = fileAccessI.write (b,0,nRead); uG5RE
} &-S;.}
catch(Exception e){e.printStackTrace ();} ]+U:8*
} )A@ }mIs"
} Ok0zgi
NmH1*w<A
g6s&nH`Z2
//打印回应的头信息 )2nx5"
public void logResponseHead(HttpURLConnection con) D.!ay>o0#
{ 5B|&+7dCw
for(int i=1;;i++) P!6v0ezN
{ (0wQ [(
String header=con.getHeaderFieldKey(i); "e3T;M+
if(header!=null) i 4}4U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IInsq
Utility.log(header+" : "+con.getHeaderField(header)); v+), uj
else 6w?l I
break; +qWrm|O]
} ~PTqR2x
} gv6}GE
Zb \E!>V
m'!smSx8
public void splitterStop() *mvDh9v
{ hc2AGeZr
bStop = true; H3}eFl=i2
} z1K}] z%
a>05Yxw
: \{>+!`w
} +i\ +bR
4!q4WQ ;
?cZ#0U
/* 0P+B-K>n
**FileAccess.java l[,RA?i {
*//文件访问(定位，写) `<?{%ja
package NetFox; (TX\vI&
import java.io.*; u|.c?fW'3
EgYM][:UU
WR;)
public class FileAccessI implements Serializable{ b`9J1p.;
,k9@%{4 l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 EMTAl;P
RandomAccessFile oSavedFile; MV(Sb:RZ
long nPos; fwN'5ep
6Mh;ld@
F2N)|C<
public FileAccessI() throws IOException sy\w ^]
{ 1"hd5a
this("",0); k2-:!IE
} |}?o=bO
CnXl 7"
-&7\do<
public FileAccessI(String sName,long nPos) throws IOException `U.VfQR:
{ u%s@B1j
oSavedFile = new RandomAccessFile(sName,"rw"); y8HwyU>
this.nPos = nPos; O(_a6s+m
oSavedFile.seek(nPos); rUz-\H(-
} doX8Tq
FX yyY-(O
"3?N*,U_
public synchronized int write(byte[] b,int nStart,int nLen) @W|N1,sp
{ !5wuBJ0
int n = -1; mY'c<>6t
try{ aFbIJm=!
oSavedFile.write(b,nStart,nLen); 3IlflXb
n = nLen; +=N!37+G
} ask76 e
catch(IOException e) x!i(M>P
{ |_} LMkU)
e.printStackTrace (); ,Fv8&tR
} _MI8P/
46(=*iT&V
4Y>J,c
return n; _Yms]QEZ
} }+m")=1{
Sc?UjEs
O:I"<w9_1
} xMpQPTte
/A4^l]H;+3
&Q>tV+*
/* k^%Kw(/
**SiteInfoBean.java fqY;>Z
*/ q!OB?03n
package NetFox; 1Z$` }a
K<g<xW*X
Ofm?`SE*|
public class SiteInfoBean { IQm[,Fh
Twi7g3}/jB
r](%9Y
private String sSiteURL; //Site's URL f6*6*=
private String sFilePath; //Saved File's Path HtN!Hgpwg
private String sFileName; //Saved File's Name -aV!ZODt
private int nSplitter; //Count of Splited Downloading File A><q-`bw
l$\OSG
P{gGvC,
public SiteInfoBean() B(zcoWQ*B
{//nSplitter的缺省值为5 01_*^iCf5
//default value of nSplitter is 5 -,Oq=w*EV
this("","","",5); U?[_ d
} p_g#iH!*
7C::%OF~7
G%q^8#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BPwn!ii|
{ }}Kjb
sSiteURL= sURL; N}/|B}
sFilePath = sPath; #J):N
sFileName = sName; +%'!+r l
this.nSplitter = nSpiltter; *?o`90HHP[
LT2UY*
FD*)@4<o
} [e6zCN^t
;WqWD-C
]}za
public String getSSiteURL() /E32^o|,>
{ *%#Sa~iPo
return sSiteURL; $-Yq?:
} q-lejVS(g
?r}'0dW
YR? ujN
public void setSSiteURL(String value) V:Lq>rs#
{ 8=T[Y`;x
sSiteURL = value; h@H8oZ[
} IHs^t/;Iv
F^/b!)4X
f7y3BWOi]
public String getSFilePath() e%wzcn
{ ;&2f{
return sFilePath; &$V&gAN
} @,i_Gw)
u;/5@ADW
/9 ^F_2'_
public void setSFilePath(String value) 0LW|5BVbIO
{ GLpl
sFilePath = value; |vUjoa'.7E
} \}p!S$`
G<_<j}=
Mcfqo0T-
public String getSFileName() \kS:u}Ip!
{ oz[Mt i*
return sFileName; H-g CY|W
} |3SM
"+{>"_KV
9ZVzIv(
public void setSFileName(String value) >bUxb-8
{ l =X6m(
sFileName = value; 4F=cER6l
} /qwl;_Jcf
9[@K4&
ri?k}XnhX
public int getNSplitter() nPRv.h
{ +f"q^RIU
return nSplitter; Q?xCb
} DN0`vl{*
D9 \!97
AC}[Qp!
public void setNSplitter(int nCount) =g3o@WD/G
{ TYH4r q &
nSplitter = nCount; DPg\y".4Y&
} r Y#^C
} q?0&&"T}
C>=[fAr mO
?? 2x*l1
/* 98ot{+/LK
**Utility.java U'oFW@Y;h
*/ 1{Kv
package NetFox; /JGET
z?M_Cz;:J
u_*DS-
public class Utility { , #nYHD
|EZ\+!8N:{
my+2@ln
public Utility() *u ^mf~
{ A8T75?lL(
GC3WB4iY@U
Tg yY 9
} |x+g5~$
YW7Pimks
//线程睡眠 E'iN==p_:
public static void sleep(int nSecond) {7Qj+e^
{ B }t529Z
try{ nAT,y9&
Thread.sleep(nSecond); VBq|j"o0"
} 0U&@;/?
catch(Exception e) 76eF6N+%}t
{ 2kkqPBc_
e.printStackTrace (); k}hTSL
} |E?,hTRe5
} ,vcd>"PK
C-tkYP
//日志 9NC?J@&B
public static void log(String sMsg) :x[SV^fw[
{ W!o|0u!D
System.err.println(sMsg); epGC Ta
} KbGz3O'u
'B9q&k%<
/I48jO^2
public static void log(int sMsg) 60--6n
{ l>*L Am5
System.err.println(sMsg); 1{-yF :A
} F S!D
} &HB!6T/
` #; "
V: n\skM
/* TOw;P:-
**TestMethod.java bc]SY =
*/ =:*2t
package NetFox; *X\J[$!
["WWaCcx
BFswqp:
public class TestMethod { +lw8YH
k"F\4M
]{ir^[A6
public TestMethod() @kWRI*m
{ ///xx/weblogic60b2_win.exe fk2p}
try{ Y2aN<>f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &P&VJLAe
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i\dd
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0b}.!k9
fileFetch.start(); ZVz`g]
} DCKH^J
catch(Exception e){e.printStackTrace ();} 9xOTR#B:_V
w5`EJp8MC
B &e'n<
} W!V-m
:B~m^5
H>F j
public static void main(String[] args) ~EM(*k._
{ ?T)M z q}
new TestMethod(); \k3EFSm
} 7O,!67+^~
} 6h7TM?lt
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