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)); c7?_46J
} O8^A5,2@3>
for(int i=0;i<nEndPos.length-1;i++) ,yC-+VL
{ #OZ>V3k
nEndPos = nStartPos[i+1]; N>Xo_-QCY
} \TIT:1
nEndPos[nEndPos.length-1] = nFileLength; ]{!U@b
} ?}qttj
} '|ad_M
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?llXd4
//启动子线程 i|c'Lbre`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U1Q:= yD
for(int i=0;i<nStartPos.length;i++) Yy5h"r
{ }~2LW" 1'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \1d(9jR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~W*FCG#E
nStartPos,nEndPos,i); E~,F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q[Z8ok
fileSplitterFetch.start(); }I2wjO
} T _r:4JS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v/@^Q1G/:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y>:N{|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1}S S+>`
nEndPos = " + nFileLength); rUwZMli
// fileSplitterFetch[nPos.length-1].start(); K'55O&2
#:jHp44J
V4hiGO[
//等待子线程结束 ><RpEnWZ<
//int count = 0; G, 44va
//是否结束while循环 p5Z"|\
boolean breakWhile = false; <5d~P/,
YD<:,|H
Moy <@+
while(!bStop) svsqg{9z
{ @>u}eB>Kn
write_nPos(); ,NOsFO-`<
Utility.sleep(500); ~Io7]
breakWhile = true; D!@Ciw
Yf:IKY
5c9^-|-T
for(int i=0;i<nStartPos.length;i++) '>NCMB{*
{ 7jxslI&F
if(!fileSplitterFetch.bDownOver) ?:pP8/y
{ d+<G1w&z
breakWhile = false; ng[Ar`
break; 8G9s<N}5&u
} H=@}=aPf
} C](f>)Dz /
if(breakWhile) dFRsm0T
break; 6RG)`bu
iyA'#bE-
C\\~E9+
//count++; :=}BN
//if(count>4) .@2m07*1
// siteStop(); -]L6=
} v;BV@E0}x
Ld\R:{M"
aL*&r~`&e'
System.err.println("文件下载结束！"); j-0z5|*KE
} lyIl-!|
catch(Exception e){e.printStackTrace ();} eds o2
} kv]~'Srk
Z"Zmo>cV4
3Ko/{f
//获得文件长度 +Um( h-;
public long getFileSize() *e<[SZzYZ
{ //*fSF
int nFileLength = -1; T{Gj+7bQ~
try{ t,QyfN
URL url = new URL(siteInfoBean.getSSiteURL()); DD7h^-x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]}*R|1
httpConnection.setRequestProperty("User-Agent","NetFox"); IW>T}@ |
;t'5},(FP
,qA(\[
int responseCode=httpConnection.getResponseCode(); 8R2QZXJb-
if(responseCode>=400) Jy^u?
{ cU RkP`
processErrorCode(responseCode); "/)#O~
return -2; //-2 represent access is error Diy8gt
} 2!0c4a^z
;ZH3{
M:XSQ["6>V
String sHeader; U [*FCD!~
VE#Wb7
c(J!~7
for(int i=1;;i++) 1cxrH+N
{ O|\J}rm'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c$ao:nP)D
//Utility.log(in.readLine()); dUsYZdQs
sHeader=httpConnection.getHeaderFieldKey(i); p%#<D9S
if(sHeader!=null) FFV `P
{ U}&2k
if(sHeader.equals("Content-Length")) Hv!U|L
{ `lQ3C{}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $Oq^jUJ
break; ]*vdSr-J
} j`oy`78O
} tU4s'J
else R,gR;Aarw
break; \Npxv
} mIurA?&7!
} 3cFf#a#
catch(IOException e){e.printStackTrace ();} AZ0;3<FfLp
catch(Exception e){e.printStackTrace ();} H+1-]'g`
,X#2\r<|
9`wZz~hL"
Utility.log(nFileLength); <nE>XAI_7
`q?8A3A
j!_;1++q
return nFileLength; H#NCi~M>3
} %4ePc-
_ <WJ7
2#P*,
//保存下载信息（文件指针位置） 3wOZ4<B
private void write_nPos() Jzj1w}?H
{ M1 :uJkO.
try{ b8~Bazk
output = new DataOutputStream(new FileOutputStream(tmpFile)); Yb+yw_5
output.writeInt(nStartPos.length); \wo?47+=
for(int i=0;i<nStartPos.length;i++) >[MX:Yh
{ `)` n(B
// output.writeLong(nPos); <%($7VMev
output.writeLong(fileSplitterFetch.nStartPos); "|Xk2U
output.writeLong(fileSplitterFetch.nEndPos); Gnf~u[T6
} >XK PTC5H
output.close(); d^RxQuA
} IHe/xQ@
catch(IOException e){e.printStackTrace ();} $8;R[SU6Y
catch(Exception e){e.printStackTrace ();} u2[iMd
} ~$ng^D
*;1,5L
ozAS[B6
//读取保存的下载信息（文件指针位置） O]lSWEe
private void read_nPos() &Nj3h(Ll
{ &f"-d
try{ {kp"nl$<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9)}[7Mg:C
int nCount = input.readInt(); pi /g H
nStartPos = new long[nCount]; ;-9=RI0
nEndPos = new long[nCount]; H(bs$C4F
for(int i=0;i<nStartPos.length;i++) F5?m6`g?
{ 'd.EC#
nStartPos = input.readLong(); 5V6G=H
nEndPos = input.readLong(); pNOwDJtK
} qC}-_u7s
input.close(); s8-<m,*
} _(Sa4Vb=Q6
catch(IOException e){e.printStackTrace ();} HGXt
catch(Exception e){e.printStackTrace ();} >*]Hq.&8
} %C$%!C
kgnmGuka
?!9)q.bW
private void processErrorCode(int nErrorCode) 3|WWo1
{ !u_Y7i3^
System.err.println("Error Code : " + nErrorCode); }lh I\q
} &S( .GdEf
VSrr`B
}2<r,
//停止文件下载 Anscr
public void siteStop() [K9'<Qnu
{ ]DOX?qI i
bStop = true; mX\TD0$d
for(int i=0;i<nStartPos.length;i++) n1~o1
fileSplitterFetch.splitterStop(); xgpi-l
8dZ0rPd?
3^R&:|,
} x$IX5:E#e
} bLe<G
//负责部分文件的抓取 &=#[(vl
**FileSplitterFetch.java >_o}
*/ &QDW9 Mi
package NetFox; U'8bdsF_
'SCidN(n
~Q?a|mV,
import java.io.*; WOQP$D9
import java.net.*; K<pV
hCCiD9gz
}2(,K[?
public class FileSplitterFetch extends Thread { X}tVmO?
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yHs-h
String sURL; //File URL dQ_!)f&w1
long nStartPos; //File Snippet Start Position ~V&aUDO>/
long nEndPos; //File Snippet End Position h(M#f7'~&
int nThreadID; //Thread's ID TR<<+
boolean bDownOver = false; //Downing is over k%D+Y(WGz8
boolean bStop = false; //Stop identical R($KSui
FileAccessI fileAccessI = null; //File Access interface jqv-D
dik:4;
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2ggdWg7z
{ ^~G8?]w
this.sURL = sURL; ^SxY IFL
this.nStartPos = nStart; MP_'D+LS
this.nEndPos = nEnd; K@#(*."
nThreadID = id; )Z(TCJ~~!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v'VD0+3[H
} &z>e5_.
V>ieh2G(
ANJ$'3tg
public void run() '<rZm=48
{ zRq-b`<7V
while(nStartPos < nEndPos && !bStop) 30XR 82P/
{ T'4z=Z]w
*8#i$w11M
%1O;fQL
try{ p$h4u_
URL url = new URL(sURL); c}y [[EX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !X"K=zt"
httpConnection.setRequestProperty("User-Agent","NetFox"); <(-3_s6-
String sProperty = "bytes="+nStartPos+"-"; !OA]s%u
httpConnection.setRequestProperty("RANGE",sProperty); !|O~$2O@
Utility.log(sProperty); U7oo$gW%|T
"Jt.lL ]5
4zJtOK?r"
InputStream input = httpConnection.getInputStream(); f2^r[kPX"
//logResponseHead(httpConnection); R,F[XI+=N
q>mE< (-M
0BH_'ZW
byte[] b = new byte[1024]; KcK>%%
int nRead; VwOW=4`6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7qj9&bEy
{ t: #6sF
nStartPos += fileAccessI.write(b,0,nRead); EGZb7:Y?
//if(nThreadID == 1) G`\f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l~6?kFy9h
} o'W5|Gy
QAvir%Y9Q
VJdIHsI
Utility.log("Thread " + nThreadID + " is over!"); ZCB_
bDownOver = true; o(:[r@Z0z
//nPos = fileAccessI.write (b,0,nRead); "Qja1TQ
} COW}o~3-4
catch(Exception e){e.printStackTrace ();} MxY/`9>E|+
} u>TZt]h8
} -[6z 1"*
5dB'&8DX
<5NF;
//打印回应的头信息 ))&;}2{
public void logResponseHead(HttpURLConnection con) m|=H#
{ q{t*34R
for(int i=1;;i++) (N&lHLy
{ ,`gl&iB
String header=con.getHeaderFieldKey(i); d/bEt&
if(header!=null) mnmP<<8C,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =$nB/K,8AX
Utility.log(header+" : "+con.getHeaderField(header)); .G+Pe'4a
else M@?xa/E64
break; p;W.lcO`0
} DdVF,
} kAu+zX>S+
pek%08VSEU
wi4=OU1L)a
public void splitterStop() 1RK=,Wx
{ ?r?jl;A&
bStop = true; 'g$(QvGF9
} 4\6N~P86
iVd.f A
(cN}Epi(D
} c05%iv
rk7QZVE
R,|d`)T
/* G(~;]xNW+
**FileAccess.java d1U\ft:gV
*//文件访问(定位，写) yQ^($#Yk
package NetFox; <o+<H
import java.io.*; ~ug= {b
]p;FZ4-T
7oq[38zB
public class FileAccessI implements Serializable{ '1$!jmY
q*2N{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RTv qls
RandomAccessFile oSavedFile; lWqrU1Sjl
long nPos; # g_Bx
RB+N IoQQ|
hWKJ,r%9;
public FileAccessI() throws IOException nv0]05.4
{ t`+'r}=d
this("",0); h}]fnA
} ~M\I;8ne
7DIIx}A
jLpc Zb,
public FileAccessI(String sName,long nPos) throws IOException cCa|YW^j
{ NcP.;u;`
oSavedFile = new RandomAccessFile(sName,"rw"); {;.T7dL
this.nPos = nPos; 2D:fJ~|-[
oSavedFile.seek(nPos); S-YM%8A[
} |]aE<`D
KyzFnVH3)
~_s{0g]B
public synchronized int write(byte[] b,int nStart,int nLen) HW7; {QMg
{ *X4PM\ck
int n = -1; !}4MN:r
try{ ,:`ND28V7
oSavedFile.write(b,nStart,nLen); JB>b`W9
n = nLen; A0fFv+RN3
} (sQr X{~
catch(IOException e) bk)g;+@
{ ND5`Q"k
e.printStackTrace (); c7M%xGrP
} !w H'b
`\m*+Bk[5
:OW;?{ ~j
return n; Bf$_XG3
} #?XQ7Im
l2&`J_"
#hlCs
} ^k Cn*&
aM{xdTYaU
&m[Qn!>i6
/* Dc+'<"
**SiteInfoBean.java ixV0|P8,c
*/ =&},;VOh
package NetFox; \4AM*lZ
?_ dIIQ
!H2QjW
public class SiteInfoBean { +Y V|ij
yB3;
l/Vo-#
private String sSiteURL; //Site's URL @]![o %
private String sFilePath; //Saved File's Path +n7?S~R$
private String sFileName; //Saved File's Name l27\diKPJ
private int nSplitter; //Count of Splited Downloading File TuW/N L|
6:]*c[7
06Gt&_Q
public SiteInfoBean() YFTjPBV
{//nSplitter的缺省值为5 ;r6jx"i
//default value of nSplitter is 5 D)@YI.T
this("","","",5); HFqm6|
} JICawj:I
meCC?YAB
W,K%c=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (?H0+zws^
{ & u!\<\
sSiteURL= sURL; YOrrkbJ(
sFilePath = sPath; NBF MN%
sFileName = sName; de]zT^&C
this.nSplitter = nSpiltter; ,&d@O>$E:
{<5ybbhLV
R@wjccu
} 5BR2?hO4
wP57Pf0
[j"9rO" +
public String getSSiteURL() *#TYqCc+g
{ {VP$J"\e
return sSiteURL; >5wx+n)/)
} |TE}`?y[g
5"/J^"!h
2jbIW*
public void setSSiteURL(String value) $46{<4.
{ \V>?Do7
sSiteURL = value; +`sv91c
} gt\MS;jMa
:d8W+|1u
cv(PP-'\
public String getSFilePath() @w>zF/
{ 0I{gJSK.,
return sFilePath; xP=/N!,#
} lKkN_ (/j
S2>c#BQ
5VO;s1
public void setSFilePath(String value) .0G6flD
{ $HG}[XD?
sFilePath = value; fA=#Fzk2
} n$aA)"A #
J>^\oAgpE
f""`cdqAOh
public String getSFileName() DOz\n|8S
{ ~w</!s
return sFileName; HK)cKzG[s!
} {T'GQz+R"
KI]wm
yIb,,!y9{
public void setSFileName(String value) \]9.zlB
{ !m(4F(!"h
sFileName = value; ]hud4i~
} >|Q:g,I
NWfAxkz{/
?k[p<Uo
public int getNSplitter() 3M0+"l(X
{ zKFp5H1!%+
return nSplitter; eh*6cQ.0
} Eh|.
K\^ 0_F K
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public void setNSplitter(int nCount) gq"k<C0
{ iU+nqY'
nSplitter = nCount; aS}1Q?cU
} &t(0E:^TRU
} #tdf>?
_28<m JfG
\tyg(srw0
/* ]l~V&#i_c
**Utility.java Sb".]>^
*/ `d2,*KR
package NetFox; 8wH.et25k
@mt0kV9
\uG`|Dn
public class Utility { -xg2q V\c
uE=$p)
m6 s7F/
public Utility() ]v G{kAnH
{ CnN9!~]"
qP!P +'B
S<nq8Ebmw
} mqfO4"lt
A\Txb_x
//线程睡眠 @^ ik[9^H
public static void sleep(int nSecond) Ovw[b2ii
{ QO{y/{
try{ -V %gVI[
Thread.sleep(nSecond); 0(8H;T
} w>xV
catch(Exception e) ]+DI.%
{ V2|3i}V"
e.printStackTrace (); XH7xT@
} BsZ{|,oQnZ
} ;oH,~|K
9H]_4?aX
//日志 D~K;~nI
public static void log(String sMsg) Ap\AP{S4
{ rAQF9O[
System.err.println(sMsg); ,%#
} EA<}[4#jS
|rRG=tG_'
]7AX%EG3
public static void log(int sMsg) lz | 64J
{ T_<BVM
System.err.println(sMsg); c:M$m3Cs?
} 02JL*
} vOI[Z0Lq9h
-m 5}#P89
RAs0]K
/* io4A>>W==/
**TestMethod.java tZWrz e^
*/ M] V.!z9B
package NetFox; {Z{o"56f
'_+9y5
^b?2N/m@
public class TestMethod { 24\gbv<
[IM%b~j(^
"L&k)J
public TestMethod() g+zJ?
{ ///xx/weblogic60b2_win.exe MN= sIP,zk
try{ JbQZ!+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^%oUmwP<$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mZ0J!QYk
SiteFileFetch fileFetch = new SiteFileFetch(bean); pF=g||gS
fileFetch.start(); H ;@!?I
} y@ek=fT%4
catch(Exception e){e.printStackTrace ();} \6j^kY=
"u')g&
0WxCSL$#I
} r@)A k
QBE@(2G}C
= Rc"^oS
public static void main(String[] args) `kBnSio~
{ Ln#a<Rx.E7
new TestMethod(); bNzqls$
} W,hWOO
} vrl[BPI
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