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)); 1"7Rs}l7
} LNm{}VJ%
for(int i=0;i<nEndPos.length-1;i++) UTT7a"
{ T;{M9W+
nEndPos = nStartPos[i+1]; c^Y&4=>T
} %UV'HcO/gp
nEndPos[nEndPos.length-1] = nFileLength; BM6 J
} @!;EW R]
} 0C3s
B-EVo&.
;}/@ar7s3
//启动子线程 KNH.4A ,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z^xrB$8 u
for(int i=0;i<nStartPos.length;i++) <]9%Pm#X
{ =~7%R.U([e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [ vWcQ6m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), srX" vF
nStartPos,nEndPos,i); q>JW$8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AL(YQ)-Cg
fileSplitterFetch.start(); %(72+B70R
} yDk|ad|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^##tk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MGoYL\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <|,0%bq)|
nEndPos = " + nFileLength); 8 oK;Tzh
// fileSplitterFetch[nPos.length-1].start(); aVI%FycYo
`/+%mKlC|[
2`|1 !x
//等待子线程结束 }\p>h
//int count = 0; ">?ocJ\9
//是否结束while循环 ?z "fp$
boolean breakWhile = false; +1`Zu$|
qJ\tc\
~KtA0BtC
while(!bStop) Y6J7N^
{ N|G=n9p
write_nPos(); oSDx9%
Utility.sleep(500); Uwd^%x*
breakWhile = true; Lbo8>L(
G|WO
v\LcZt`}
for(int i=0;i<nStartPos.length;i++) &PfCY{_
{ z?a<&`W
if(!fileSplitterFetch.bDownOver) 0H|U9
{ $m$tfa-
breakWhile = false; =e<;B_~.
break; y1zNF$<q
} m%mA0r
} ?B&Z x-krd
if(breakWhile) !y1]S .;
break; %FN3/iM
t6zc$0-j"
*""JE'wG
//count++; \M@9#bd
//if(count>4) @ P[o
// siteStop(); pH#*:v!)
} yS*s[vT
p^=>N9
n9qO;X4&
System.err.println("文件下载结束！"); cyR K&J
} :j sa.X
catch(Exception e){e.printStackTrace ();} F4=+xd >0
} ~S5wfx&
MT`gCvoF4P
a,B2;4"
//获得文件长度 x2 s%qZ#
public long getFileSize() 1-HL#y*7$
{ }]8n3&*
int nFileLength = -1; D/T&0
try{ HkGA$
URL url = new URL(siteInfoBean.getSSiteURL()); H,/|pP.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dMcCSwYh
httpConnection.setRequestProperty("User-Agent","NetFox"); ,34|_
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]Bpdb'
int responseCode=httpConnection.getResponseCode(); |2!!>1k
if(responseCode>=400) XxN=vL&m
{ i\4Qv"%
processErrorCode(responseCode); ||{V*"+\
return -2; //-2 represent access is error 5kX#qT=
} uVO*@Kj+
Pc=S^}+
1x\Vz\
String sHeader; M5mCG
.GJl@==~1
R"j6 w[tn
for(int i=1;;i++) y:FxX8S$'e
{ ER z@o_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fB\+.eN
//Utility.log(in.readLine()); AnB]f~Yjl
sHeader=httpConnection.getHeaderFieldKey(i); 9t`Z_HwdCb
if(sHeader!=null) MhE'_sq
{ 8 *Fr=+KN
if(sHeader.equals("Content-Length")) sd (I@ &y
{ -c^/k_n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -EwtO4vLJ
break; P)7_RE*gY
} /F>\-
} x~7_`=}rO
else Je|D]w
break; |sM#nhxK
} amPC C
} Hk65c0
catch(IOException e){e.printStackTrace ();} 6 (:^>@
catch(Exception e){e.printStackTrace ();} X>i`z
Ch`nDIne
0YMmWxV
Utility.log(nFileLength); s_(%1/{
uYh6q1@"~
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return nFileLength; 3 cd5g
} d+9T}? T:*
,zCrix 3
u )'l|Y
//保存下载信息（文件指针位置） l\vvM>#S
private void write_nPos() njz:7]>e
{ Tk9/1C{8
try{ M4;A4V=W
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^7l.!s#$b
output.writeInt(nStartPos.length); [+=h[DC
for(int i=0;i<nStartPos.length;i++) V;b^b5yZ>
{ _g%Wx?K9
// output.writeLong(nPos); T>"GH M
output.writeLong(fileSplitterFetch.nStartPos); Ek!$Ary
output.writeLong(fileSplitterFetch.nEndPos); 4r@dV%:%<
} \O]1QM94Y
output.close(); 7l-`k
} PI"&-lXI-m
catch(IOException e){e.printStackTrace ();} ?0Xt|
catch(Exception e){e.printStackTrace ();} <lk_]+ XJ3
} "@xF(fyg
l:!4^>SC
bL=32YS
//读取保存的下载信息（文件指针位置） /]/3)@wT
private void read_nPos() :U5>. ):
{ ^k&T?uU
try{ d|,,,+fS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jg ~;s
int nCount = input.readInt(); 3I)!.N[m
nStartPos = new long[nCount]; G\ twx ;
nEndPos = new long[nCount]; V24i8Qx
for(int i=0;i<nStartPos.length;i++) !ul)e;a
{ Sb&sW?M
nStartPos = input.readLong(); )^&,[Q=i
nEndPos = input.readLong(); M2[ywab
} b";w\H
input.close(); RI#Cr+/
} 4|+6a6
catch(IOException e){e.printStackTrace ();} D`r^2(WW
catch(Exception e){e.printStackTrace ();} a8?Zb^
} H}}]Gh.T
X&^8[,"
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private void processErrorCode(int nErrorCode) 3r=IO#
{ cmQLkT"#K
System.err.println("Error Code : " + nErrorCode); JwzA'[tM
} w%,Iy,G@
tS2P|fl
]xf lfZ
//停止文件下载 7y",%WYSD
public void siteStop() xg~ Baun
{ MSPzOJQPy
bStop = true; K5x&:z
for(int i=0;i<nStartPos.length;i++) #]G$o?@Y=^
fileSplitterFetch.splitterStop(); ziuhS4k
H'uRgBjWJ
dZ UB
} w.qpV]9>
} aHKv*-z-
//负责部分文件的抓取 B\2<r5|QG
**FileSplitterFetch.java $'}:nwq6x
*/ + M2|-C
package NetFox; tzv&E0|d
)W&H{2No
f=v+D0K$n
import java.io.*; MVV9[f
import java.net.*; N|eus3\E
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@?_<A%hz
public class FileSplitterFetch extends Thread { qyMR0ai-
ZHxdrX)
\WD}@6) ~
String sURL; //File URL 3n']\V
long nStartPos; //File Snippet Start Position |F36^
long nEndPos; //File Snippet End Position q#Y%Y
int nThreadID; //Thread's ID 4#mRLs'
boolean bDownOver = false; //Downing is over MD~03
boolean bStop = false; //Stop identical gIS<"smOo
FileAccessI fileAccessI = null; //File Access interface }q-_|(b;
ugg08am!
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >Pv#)qtm
{ ]|[,N>
this.sURL = sURL; rlYAy5&
this.nStartPos = nStart; Q4Mp[
this.nEndPos = nEnd; T78`~-D4<
nThreadID = id; l]whL1N3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kUAjQ>
} 2<Pi2s'
vMJv.O>HW
tk4~ 8
public void run() yG?,8!/]
{ /jih;J|
while(nStartPos < nEndPos && !bStop) #SQao;>
{ 4os7tx
Wa~'p+<c~b
pR2QS
try{ E1:{5F5/
URL url = new URL(sURL); b,YTw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sW 7R&t!G
httpConnection.setRequestProperty("User-Agent","NetFox"); ]Y;EIn
String sProperty = "bytes="+nStartPos+"-"; 79<{cexP
httpConnection.setRequestProperty("RANGE",sProperty); `,ZsKxI
Utility.log(sProperty); i'|rx2]e
hKb-l`KO
me@4lHBR
InputStream input = httpConnection.getInputStream(); X b-q:{r1h
//logResponseHead(httpConnection); A P><l@
g"|QI=&_J
o Y_(UIa
byte[] b = new byte[1024]; Kx?3]
int nRead; qve2?,i8hM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yyfm
{ {:c*-+?
nStartPos += fileAccessI.write(b,0,nRead); YuD2Q{
//if(nThreadID == 1) w\KO1 Ob
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PgAC3%M6
} YC4S,fY`
fkWuSGi
G8OLx+!0e
Utility.log("Thread " + nThreadID + " is over!"); $O,$KAC
bDownOver = true; 2SEfEkk
//nPos = fileAccessI.write (b,0,nRead); g@YJ#S(}
} AQ 3n=Lr
catch(Exception e){e.printStackTrace ();} 1HxE0>
} j}Lt"r2F
} |xyN#wi
JnH>L|G{;%
~p<o":k+Lv
//打印回应的头信息 /g2(<
public void logResponseHead(HttpURLConnection con) "ZF:}y
{ ! %r5
for(int i=1;;i++) x2+%.$'
{ HMJx[ yD
String header=con.getHeaderFieldKey(i); M >Yx_)<U
if(header!=null) 4AB7uw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )~;=0O |X
Utility.log(header+" : "+con.getHeaderField(header)); Ua]shSjyI
else T(K~be
break; j K?GB
} c.m8~@O5+
} j`Fsr?]/
/>_Mz
D Cx3_
public void splitterStop() B25@6
{ vtG_A{l
bStop = true; )]L:OE
} oe,L&2Jz@
Ej>5PXp'2
l'HrU 1_7Y
} qT^R>p
ta_!
5mdn77F_
/* {\ vj":
**FileAccess.java ^yg`U(
*//文件访问(定位，写) i>i@r ;:|
package NetFox; azKbGS/X
import java.io.*; {0F\Y+
:VC#\/f
, A?o
public class FileAccessI implements Serializable{ wmdvAMN
}Wjb0V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 szN`"Yi){
RandomAccessFile oSavedFile; +xMK.*H]W
long nPos; L}lOA,EF
E#X1P #$pW
!mH2IjcL
public FileAccessI() throws IOException >Du5B&41
{ C4e3Itc9X
this("",0); $EHAHNL?Lx
} d-nqV5
JaP2Q} &B
X(kyu,w
public FileAccessI(String sName,long nPos) throws IOException O0Y/y2d
{ @SeE,<
oSavedFile = new RandomAccessFile(sName,"rw"); j4Ppn
this.nPos = nPos; We%-?l:"
oSavedFile.seek(nPos); Q.Uyl:^PxU
} 0\#uxzdhJ
DZKVZ_q
i&\N_PUm[
public synchronized int write(byte[] b,int nStart,int nLen) 5fuOl-M0W
{ DJP)V8]!B
int n = -1; 6T0[ ~@g5
try{ 9MA/nybI
oSavedFile.write(b,nStart,nLen); v`evuJ\3
n = nLen; eU?SLIof[{
} H~JPsS;
catch(IOException e) 91|=D \8aE
{ is?H1V~8`$
e.printStackTrace (); k ]C+/
} V}(snG,
|uVhfD=NG
FC+K2Yf1=0
return n; ~Q%C>
} #?L%M
:[P>e ox
{` Bgxejf
} N)G.^9
tep_g4CQR_
&>43l+
/* JVE]Qb_
**SiteInfoBean.java +ou5cQ^
*/ Yoi4R{9c
package NetFox; "MZj}}l
;Q>(%"z};
m:A7*r[
public class SiteInfoBean { tgEXX-{
1^rODfY0
.PBma/w W
private String sSiteURL; //Site's URL pv1J6
private String sFilePath; //Saved File's Path xo/[,rR
private String sFileName; //Saved File's Name qV0C2jZ2
private int nSplitter; //Count of Splited Downloading File 1"{3v@yi
e.9oB<Etp
m@ b~
public SiteInfoBean() EdxTaR
{//nSplitter的缺省值为5 zS*GYE(l^
//default value of nSplitter is 5 ~t\Hb8o
this("","","",5); BoJ@bOe#
} 3{B`[$
Iu`eQG
r#LoBfM;^A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) . fq[>zG'&
{ fOtin[|}6@
sSiteURL= sURL; #"% ]1={b
sFilePath = sPath; \Ku6gEy
sFileName = sName; C=2"*>lTn
this.nSplitter = nSpiltter; 4Sv&iQ=vh
Z[:fqvXQ
s8iJl+Jm
} L>Bf}^
'}h[*IB}5
qg?O+-+
public String getSSiteURL() Fn0Rq9/@
{ /Y|oDfv
return sSiteURL; tkU"/$Vi\
} QHnk@R!
-ZqN~5>j)
*fVs|
public void setSSiteURL(String value) ~yz7/?A)TS
{ -#T?C]}
sSiteURL = value; )P>Cxzs
} I4 dS,h
bJ8G5QU
(@Q@B%!!K
public String getSFilePath() 3#vhQ*xU
{ fhlhlOg
return sFilePath; 2)(P;[m^o
} r J'm>&Ps
vB(tpki|
H@%Y!z@\
public void setSFilePath(String value) * bx%hX
{ .lm^+1}r
sFilePath = value; lgp-/O"T
} biFy*+|
{'P7D4w
^Z]1Z
public String getSFileName() $'!r/jV
{ N9IBw',
return sFileName; WF#eqU*&
} ka3Jqy4[
sS#Lnj^`%
;\yY*
public void setSFileName(String value) `h+ia/
{ wlr/zquAE9
sFileName = value; R:HF~}
} cd,)GF
H/m -$;cF3
CbTYt6DC
public int getNSplitter() 6u^MfOc
{ rxtp?|v9
return nSplitter; r<4FF=
} {2?o:
qv|geBW
7N0V`&}T
public void setNSplitter(int nCount) .} <$2.
{ J5PXmL
nSplitter = nCount; aV3:wp]Gn
} `PK1zSr
} T^YdAQeE
iW\cLp "
*ZP$dQ
/* bp Q/#\Z
**Utility.java V~p/P
*/ :X7"fX
package NetFox; D>wq4u
t~m >\(&
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public class Utility { pX3Q@3,$
mEsOYIu{
Nb/W+& y
public Utility() Ia-`x/r*m
{ E'qGKT
>g8H
D.?Rc'yD
} :^".cs?g
luD.3&0n
//线程睡眠 W.b?MPy]
public static void sleep(int nSecond) b,U"N-6
{ $w{!}U2+-
try{ x#z}A&
Thread.sleep(nSecond); %7WQb]y
} Z}74% 9qE
catch(Exception e) B[k {u#Kp
{ )!2$yD
e.printStackTrace (); YB{hQ<W
} a~>.
} rMkoE7n
!#P|2>>u
//日志 63R?=u@
public static void log(String sMsg) _kR);\V.8
{ yxq+<A4,a
System.err.println(sMsg); .9X,)^D
} &c<0g`x
a?#v,4t^
KICy! "af
public static void log(int sMsg) aq/'2U 7
{ tHgn-Dhzr
System.err.println(sMsg); ge*(w{|x
} =?fxPT[1K
} r9[{0y!4
#4uuT?!
RK%N:!fq=
/* CSF-2lSG
**TestMethod.java FJ]BB4 K
*/ J+oK:tzt8
package NetFox; 6;rJIk@Fx=
z3RD*3b
U1zcJl^
public class TestMethod { m]t`;lr<
P~Ss\PT
4LY kK/:
public TestMethod() ~Y=v@] 2/
{ ///xx/weblogic60b2_win.exe ];cJIa
try{ + ;u<tA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )+ }\NCFh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D*!p8J8Ku
SiteFileFetch fileFetch = new SiteFileFetch(bean); <)01]lKH
fileFetch.start(); *xY}?vSs
} %-C
catch(Exception e){e.printStackTrace ();} pRS+vV3
sp%EA=: E
Jv*[@ -.k
} rGjP|v@3^
iDp'M`(6h
ico%_fp
public static void main(String[] args) xb`,9.a7
{ ktQMkEj#
new TestMethod(); YK(I'
} 09FHE/L
} ~dkN`1$v
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