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)); t4HDt\}&k~
} St9+/Md=jQ
for(int i=0;i<nEndPos.length-1;i++) Y;qA@|
{ [Ol}GvzJ7
nEndPos = nStartPos[i+1]; #fT1\1[]
} ~r(/)w\
nEndPos[nEndPos.length-1] = nFileLength; /eFudMl
} 2RW^Nqc9
} Y<1]{4Wt
';T=kS<^_
47]?7GU,
//启动子线程 fg[]>:ZT.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SU.9;I !
for(int i=0;i<nStartPos.length;i++) `8 Q3=^)3
{ gD$bn=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sf""]c$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "v%|&@
nStartPos,nEndPos,i); /%O+]#$`0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^uG^XY&ItC
fileSplitterFetch.start(); Ed&;d+NM
} W=Y?_Oz
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -s]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JQ9JWu%a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %M?A>7b
nEndPos = " + nFileLength); 2y_R05O0
// fileSplitterFetch[nPos.length-1].start(); M{sn{
Ojea~Y]Sr
|[%CFm}+?
//等待子线程结束 Glz yFj
//int count = 0; RDFOUqS
//是否结束while循环 P1\:hh
boolean breakWhile = false; +Ndo$|XCy]
;{@jj0h;
FPg5!O%
while(!bStop) Z.!tp
{ ,ypD0Q
write_nPos(); 4VPJv>^
Utility.sleep(500); Y$tgz)
breakWhile = true; ZW+[f$X
<4DSk9/
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for(int i=0;i<nStartPos.length;i++) ,B^NH7A:
{ .tFMa:
if(!fileSplitterFetch.bDownOver) |{)SLvlJl
{ :)cn&'l(S
breakWhile = false; P:`tL)W_
break; e+_~a8 -|
} PxqRb
} |Wo_5|E
if(breakWhile) ~c;D@.e\
break; \1^qfw
N.j?:
~\0uy3%
//count++; T*m;G(
//if(count>4) #zRT
// siteStop(); ,F4_ps?(
} qa|"kRCO
VW," dmC
9lT6fW`v1Q
System.err.println("文件下载结束！"); R78=im7
} \&|zD"*
catch(Exception e){e.printStackTrace ();} k{{iF
} i2h,=NHJh?
>n`!S`)9{
C^dnkuA
//获得文件长度 ow,4'f!d
public long getFileSize() )JYt zc
{ !a(#G7zA
int nFileLength = -1; wK0= I\WN9
try{ n\U3f M>N
URL url = new URL(siteInfoBean.getSSiteURL()); mAI<zh&SQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ax'jNol
httpConnection.setRequestProperty("User-Agent","NetFox"); |l*#pN&L
i/Nd
Wix/Az
int responseCode=httpConnection.getResponseCode(); &n|S:"B
if(responseCode>=400) Y<A593
{ j|WuOZm\0
processErrorCode(responseCode); ISp'4H7R+N
return -2; //-2 represent access is error G:n,u$2a<
} /^BaQeH?R
9PpPAF
LTSoo.dE
String sHeader; !W^b:qjJ
!!WSGZUR
^p'iX4M
for(int i=1;;i++) I eQF+Xz
{ ;OE=;\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q%x |
//Utility.log(in.readLine()); 3A~53W$M
sHeader=httpConnection.getHeaderFieldKey(i); n'dxa<F2|
if(sHeader!=null) Pk94O
{ 3IrmDT
if(sHeader.equals("Content-Length")) Do&em8i z
{ R0 g-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1|+Zmo"
break; ka3(sctZ5
} 3L;GfYr0
} ujo3"j[b
else 4bT21J37
break; (l|:$%[0
} ywPFL/@
} OS X5S:XS
catch(IOException e){e.printStackTrace ();} v|VfSLZTb
catch(Exception e){e.printStackTrace ();} xB%Felz
Rh:@@4<
B%|cp+/
Utility.log(nFileLength); 8T}Ycm5}
eyx;8v cM
B{:JD^V!
return nFileLength; h4j{44MT
} &=seIc>x@
qyfw$$X
d[b(+sHp a
//保存下载信息（文件指针位置） FwdRM)1)
private void write_nPos() F]#rH
{ O<@S,/Q4
try{ U[!x 0M
output = new DataOutputStream(new FileOutputStream(tmpFile)); $@[`/Uh
output.writeInt(nStartPos.length); Jgf73IX[
for(int i=0;i<nStartPos.length;i++) #$<7
{ yK1Z&7>J>
// output.writeLong(nPos); 3c#CEuu
output.writeLong(fileSplitterFetch.nStartPos); kJ;fA|(I
output.writeLong(fileSplitterFetch.nEndPos); `M "O #
} ?qn0].
output.close(); hkSK;
} rv(Qz|K@
catch(IOException e){e.printStackTrace ();} /Dn,;@ZwAi
catch(Exception e){e.printStackTrace ();} U%swqle4
} +m> %(?=A
t+R8{9L-
KUr}?sdz
//读取保存的下载信息（文件指针位置） R'#[}s
private void read_nPos() ;8Z\bHQ>
{ N8<Wm>GLX~
try{ +/g/+B_b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $oefG}h2
int nCount = input.readInt(); 9~6FWBt
nStartPos = new long[nCount]; ^Fy{Q*p`(
nEndPos = new long[nCount]; Qx9lcO_
for(int i=0;i<nStartPos.length;i++) a0vg%Z@!
{ 8s,B,s.
nStartPos = input.readLong(); Vb=Oz
nEndPos = input.readLong(); YS}uJ&WoF
} QzjLKjl7p4
input.close(); ^%^~:<N
} g$++\%k&
catch(IOException e){e.printStackTrace ();} i+I%]
catch(Exception e){e.printStackTrace ();} LuM[*_8
} rek89.p
E^I|%F
G0Q8"]
private void processErrorCode(int nErrorCode) ]Zfg~K(
{ REyk,s2"6
System.err.println("Error Code : " + nErrorCode); @O;gKFx
} &^R0kCF`
qOyg&]7
{x3"/sF
//停止文件下载 V!eq)L
public void siteStop() @`qhQ
{ xt! DS0|*Y
bStop = true; <2cl1Fb
for(int i=0;i<nStartPos.length;i++) &cty&(2p
fileSplitterFetch.splitterStop(); -t92!O
AE:IXP|c
'USol<
} hOI|#(-
} &E@8 z&
//负责部分文件的抓取 ]fN\LY6p
**FileSplitterFetch.java 5jj<sj!S
*/ PD@]2lY(
package NetFox; ,W"[q~
(T1)7%Xs
'\I.P
import java.io.*; p'lL2n$E
import java.net.*; ;&|MNN^
gZ!vRO<%
wnaT~r@U'
public class FileSplitterFetch extends Thread { aS^ 4dEJ
"3kIQsD|j
/{eD##vhP
String sURL; //File URL sN6R0YW
long nStartPos; //File Snippet Start Position gO0X-fN8
long nEndPos; //File Snippet End Position g]^@bxdg
int nThreadID; //Thread's ID }Y/uU"t
boolean bDownOver = false; //Downing is over x|#R$^4CY
boolean bStop = false; //Stop identical JXG%Cx!2}
FileAccessI fileAccessI = null; //File Access interface \KlOj%s
S4/CL4=
z(sfX}%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qpo3b7(N
{ #nQZ/[|
this.sURL = sURL; ac8+?FpK #
this.nStartPos = nStart; +|#lUXC
this.nEndPos = nEnd; !d@qT.
nThreadID = id; WJefg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h J*2q"
} Lh0qB)>
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s?=v@|vz)
public void run() _#6_7=g@s6
{ un{LwZH
while(nStartPos < nEndPos && !bStop) _9%R U"
{ /%E X4 W
s-V5\Lip,
u:~2:3B
try{ >w,o|
URL url = new URL(sURL); idWYpU>gC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZT*RD2,
httpConnection.setRequestProperty("User-Agent","NetFox"); +Y7"!wYR>
String sProperty = "bytes="+nStartPos+"-"; #S?xRqkc
httpConnection.setRequestProperty("RANGE",sProperty); ('H[[YODh
Utility.log(sProperty); ~j%g?;#*
5)g6yV'
{)E)&lL
InputStream input = httpConnection.getInputStream(); ao2NwH##
//logResponseHead(httpConnection); ~>h_#sIBC
,{"%-U#z
)bJS*#
byte[] b = new byte[1024]; vbH?[Zr?
int nRead; PuKT0*_ 7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OEz'&))J
{ (9!$p|d*
nStartPos += fileAccessI.write(b,0,nRead); A*;I}F
//if(nThreadID == 1) ya[][!.G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MHh>~Y(h
} ]njObU)[zr
F` /mcyf
=og5Mh,
Utility.log("Thread " + nThreadID + " is over!"); x|>N
bDownOver = true; gIGyY7{(s8
//nPos = fileAccessI.write (b,0,nRead); ~s#vP<QHa
} wR)U&da`@
catch(Exception e){e.printStackTrace ();} tO0MYEx"
} A 9I5
} @'go?E)f
99GzhX_
gXrPZ|iS
//打印回应的头信息 r_m*$r~f
public void logResponseHead(HttpURLConnection con) -0Ws3
{ a: Ch"la
for(int i=1;;i++) 8SV.giG;
{ S;pKL,d>r
String header=con.getHeaderFieldKey(i); l~|x*JTq
if(header!=null) uBdS}U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _gAU`aO^
Utility.log(header+" : "+con.getHeaderField(header)); " 3ryp A
else uVnbOqR<X
break; y5"b(nb
} +M@,CbqD
} H0!W:cIS;l
;,d^=:S6@
x4b.^5"`:
public void splitterStop() (jR7D"I
{ "])yV
bStop = true; 6V[ce4a%
} \^l273
I_QWdxn
T7F)'Mx<
} 2)_Zz~P^f
IP#w
BZ2frG\0&I
/* s&>U-7fx"
**FileAccess.java %(f&).W
*//文件访问(定位，写) ssf.ef$
package NetFox; @-^jbmu^ P
import java.io.*; bl/tl_.p00
y(^hlX6gQ
+(a}S$C
public class FileAccessI implements Serializable{ h-0#h/u>M
w6b\l1Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xN^ngRg0
RandomAccessFile oSavedFile; ?^y!}(
long nPos; Qyh_o
VLLE0W _]
d&N[\5q
public FileAccessI() throws IOException rMV<}C ^
{ gb_r <j:w
this("",0); @;^7kt
} <i<[TPv";
#CRAQ#:45(
wD*z >v$
public FileAccessI(String sName,long nPos) throws IOException !(%^Tg=
{ m+jW+
oSavedFile = new RandomAccessFile(sName,"rw"); Cf~H9
this.nPos = nPos; pwu8LQ3b{O
oSavedFile.seek(nPos); !YM;5vte+
} #$W bYL|
\Z?.Po`!j
-XbO[_Wf
public synchronized int write(byte[] b,int nStart,int nLen) {pzu1*
{ 5V"Fy&}:
int n = -1; $|0?$U7!
try{ 5eP0W#
oSavedFile.write(b,nStart,nLen); ,McwPHEMB
n = nLen; c8R#=^ DD
} t<UtSkE1
catch(IOException e) fo$5WTY
{ 58vq5j<V
e.printStackTrace (); 4u!<3-3Zy
} <@+>A$~0
}3^b1D>2O
4`KQ@m
return n; W*S!}ZT`
} ;!k{{Xndd
gwm}19JC
f:w#r.]
} !623;
|z]O@@j$
Xp_3EQl
/* *>=|"ff
**SiteInfoBean.java ".@}]z8
*/ nQ\)~MKd
package NetFox; 'N7AVj
dn? #}^,"
QqF&lMH
public class SiteInfoBean { 9f wFSJx
&5x ]9
-pF3q2zb
private String sSiteURL; //Site's URL $ts%SDM
private String sFilePath; //Saved File's Path uU|fCwQt
private String sFileName; //Saved File's Name Z'u:Em
private int nSplitter; //Count of Splited Downloading File )P)Zds@F
| e&v;48
]j^V5y"
public SiteInfoBean() 2c%*u {=:
{//nSplitter的缺省值为5 #iZ%CY\
//default value of nSplitter is 5 BGe&c,feIc
this("","","",5); $<]G#&F
} C>A*L4c]F
JQ[~N-
@P$_2IU"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f^EDiG>b`
{ /d1 B-I
sSiteURL= sURL; 65@,FDg*i
sFilePath = sPath; kS\A_"bc
sFileName = sName; Msk^H7
this.nSplitter = nSpiltter; xlhc`wdm
96 oztUK
Dej2-Y
} & rsNB:!
zG[GyyAQ
vv9=g*"j
public String getSSiteURL() qYwEPGa\
{ O<:"Irq\qr
return sSiteURL; [|:kS
} ;:^^Qfp
1=9M@r~ ^
H*h7Y*([
public void setSSiteURL(String value) +OM9v3qJ
{ 5LIbHSK
sSiteURL = value; gM5`UH|
} O|Z5SSlk
mvCH$}w8&
NrNxI'MG
public String getSFilePath() Z^fkv
{ (,i&pgVZ
return sFilePath; F5Xj}`}bq
} OJ/l}_a
`Dn"<-9:
O%Mi`\W@
public void setSFilePath(String value) (|*CVI;
{ 7I_1Lnnf
sFilePath = value; q@"0(Oj
} Bq20U:f
A-8[8J
`Tt;)D
public String getSFileName() )J['0DUrZK
{ \dq}nOsX*
return sFileName; l<89[{9o
} FA+'E
{hE\ECT-
_xyq25/
public void setSFileName(String value) Zeeixg-1<
{ npJyVh47
sFileName = value; 3Dm`8Xt
} 7M#irCX
)PU_'n=>
`!JcQ'u
public int getNSplitter() #cZ<[K q6
{ [5iBXOmpS=
return nSplitter; /uyZ[=5
} 2brxV'tk
|#)S`Ua1
1U/ dc.x5
public void setNSplitter(int nCount) %]iDhXLr
{ g aq"+@fH
nSplitter = nCount; -q8R'?z[
} y|e@zf
} Pf4b/w/
wB~5&:]jr
{]F};_
/* .[qm>j,
**Utility.java qi&;2Yv
*/ C.& R,$
package NetFox; @gn}J'
fBi6% #
Rl%?c5U/$
public class Utility { : }q~<
_UqE -+&
nKO4o8js{{
public Utility() D=0^"7K
{ -VO&#Mt5u
?_VoO
4$wn8!x2|
} 3O'6 Ae
X}W4dpU,
//线程睡眠 Ow@}6&1
public static void sleep(int nSecond) /jtU<uX
{ v{T%`WuPRf
try{ s_p\ bl.
Thread.sleep(nSecond); FVgE^_
} /3!c ;(
catch(Exception e) DC-tBbQkk
{ 'Pm.b}p<
e.printStackTrace (); hA6D*8oXD
} $r'PYGn
} <uYeev%
kw gsf5[
//日志 0?{Y6:d+
public static void log(String sMsg) qSg=[7XOO
{ 4dgo*9
System.err.println(sMsg); MKr)6PG,
} 0[O."9
6N<v&7cSB
G|h@O'
public static void log(int sMsg) *MG*]\D
{ 5r-OE-U{
System.err.println(sMsg); .:nV^+)
} C~r(*nr
} A.%MrgOOX
,?k~>,{3
,*r}23
/* z87_/(nu
**TestMethod.java u51%~
*/ qTA,rr#p0
package NetFox; DA(ur'D
/p PSo
TJhzyJ"t
public class TestMethod { X;vfbF
~:ldGfb|
*>#mI/#}
public TestMethod() T0Kjnzs
{ ///xx/weblogic60b2_win.exe naHQeX;
try{ gl$Ks+od
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _>LI[yf{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V(5=-8k
SiteFileFetch fileFetch = new SiteFileFetch(bean); |RA|nu
fileFetch.start(); &-hz&/A,
} >B~vE2^tQ~
catch(Exception e){e.printStackTrace ();} !gKz=-C
1\{_bUZ&
eM1=r:jgE
} \{RMj"w:
R=ipK63
4L`<xX;:{
public static void main(String[] args) v[*&@aW0n
{ MB:VACCr
new TestMethod(); M#?^uu'
} p3L0'rY|+
} ;G=:>m~
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