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)); i&>^"_4rc
} }jCO@v;
for(int i=0;i<nEndPos.length-1;i++) i;^lh]u
{ +=E\sEe
nEndPos = nStartPos[i+1]; vK)'3%
} Zo&i0%S\E
nEndPos[nEndPos.length-1] = nFileLength; i-v: %
} R%RbC!P
} >JE+j=
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;99oJD,
//启动子线程 crb^TuN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rt*x[5<
for(int i=0;i<nStartPos.length;i++) 88_ef7w
{ b:F;6X0~Hl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PEvY3F}_rh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [oU\l+t
nStartPos,nEndPos,i); f5 bq)Pm&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Uyb0iQ-,s
fileSplitterFetch.start(); iZn0B5]ikj
} x>EL|Q=?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L3Y,z3/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;9z|rWsF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *G.vY#h
nEndPos = " + nFileLength); b VEJ
// fileSplitterFetch[nPos.length-1].start(); %RV81H9B
2QaE&8vW
~_EDJp1J
//等待子线程结束 >p-UQc
//int count = 0; 6a,8t
//是否结束while循环 o664b$5nsI
boolean breakWhile = false; :%sBY0 yF
gf8o~vKX$G
%evb.h)
while(!bStop) aNu.4c/5
{ \09A"fs{
write_nPos(); fVn4=d6X
Utility.sleep(500); 06Wqfzceb
breakWhile = true; %9>w|%+;U+
F@Sk=l(
z<55[~3
for(int i=0;i<nStartPos.length;i++) F&wAre<
{ =8 @DYz'
if(!fileSplitterFetch.bDownOver) N[W#wYbH
{ 0C :8X
breakWhile = false; j_g(6uZhz3
break; j ^j"w(a
} XF(D%ygeC
} =Iop
if(breakWhile) myfTztJ
break; 6{.U7="
eB#I-eD
qg#YQ'vWte
//count++; UnK7&Uo
//if(count>4) a4ViVy
// siteStop(); ]\^O(BzB
} {BJ>x:2
]YI9
eX#.Zt]
System.err.println("文件下载结束！"); 9o>D Uc
} CPy>sV3Ru0
catch(Exception e){e.printStackTrace ();} Z4/D38_
} &/UfXKr
+45SKu=
c~(61Sn]
//获得文件长度 q{&c?l*2
public long getFileSize() oH=?1~e
{ D-{*3?x
int nFileLength = -1; gPCf+>X{
try{ 4ekwmw(ox
URL url = new URL(siteInfoBean.getSSiteURL()); Cl&mz1Y;]1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4E.9CjN1>
httpConnection.setRequestProperty("User-Agent","NetFox"); ppz3"5
%l!A%fn(
imif[n+]}d
int responseCode=httpConnection.getResponseCode(); l[i4\ CT
if(responseCode>=400) \#%GVru!
{ 23r(4
processErrorCode(responseCode); qj_0 td$
return -2; //-2 represent access is error ~b]enG5xS4
} >gp53\
&7\}Sqp
wIi(\]Q
String sHeader; Dazm8_x
t)W=0iEd9
jm%s#`)g
for(int i=1;;i++) K^<?LXJF
{ H[.)&7M\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;&=jSgr8
//Utility.log(in.readLine()); SN@>mpcJS
sHeader=httpConnection.getHeaderFieldKey(i); -OJ<Lf+"=
if(sHeader!=null) !+3&%vQ)
{ U3&GRY|##
if(sHeader.equals("Content-Length")) `C: 7N=9
{ D'!JV1Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gamB]FPZ
break; s\mA3t
} 8:& !F`o
} < +*
else =,zB|sjn
break; P+f}r^4}
} Kfb(wW
} FUL3@Gb$UV
catch(IOException e){e.printStackTrace ();} ({rcH.:
catch(Exception e){e.printStackTrace ();} DRm`y>.
lU!_V%n
`_cv& "K9f
Utility.log(nFileLength); -crMO57/
a&JY x
3}\z&|
return nFileLength; /g>-s&w
} y%vAEQ2j=
q`p0ul,n
)]q Qgc&
//保存下载信息（文件指针位置） ?rOj?J9
private void write_nPos() `WH$rx!
{ 2+y wy^
try{ ied1+H
output = new DataOutputStream(new FileOutputStream(tmpFile)); >g !Z|ju
output.writeInt(nStartPos.length); H_f8/H
for(int i=0;i<nStartPos.length;i++) ?S& yF
{ p7> 9 m
// output.writeLong(nPos); % WDTnEm
output.writeLong(fileSplitterFetch.nStartPos); .iR<5.
output.writeLong(fileSplitterFetch.nEndPos); Nsh/
} *e [*
output.close(); (km $qX
} XdA]);,
catch(IOException e){e.printStackTrace ();} I<RARB-j
catch(Exception e){e.printStackTrace ();} NB<8M!X/
} ?<4pYEP
b * \ oQ
Ry}4MEq]
//读取保存的下载信息（文件指针位置） 2fkyz
private void read_nPos() &*/= `=:C8
{ uT=r*p(v
try{ S8AbLl9G@>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TP#Ncqh
int nCount = input.readInt(); Io<T'K
nStartPos = new long[nCount]; "Q+wO+}6
nEndPos = new long[nCount]; ZB1%Kn#zo4
for(int i=0;i<nStartPos.length;i++) (5] [L<L
{ IN3-ZNx
nStartPos = input.readLong(); (pCHj'
nEndPos = input.readLong(); ffk>IOH
} w!<e#Z]3b
input.close(); !x-__[#
} 3M?O(oO
catch(IOException e){e.printStackTrace ();} OP+*%$wR
catch(Exception e){e.printStackTrace ();} %|x9C,0p#
} u\ 7Y_`8
JJ1>)S}X-
Q^va+O
private void processErrorCode(int nErrorCode) !+$QN4{9
{ ;5;>f)diS
System.err.println("Error Code : " + nErrorCode); l4$ sku-
} L *\[;.mk
9j^rFG!n
1d+Kn Jy
//停止文件下载 9LPXhxNwB
public void siteStop() @BLB.=
{ &iu]M=Yb
bStop = true; >k\p%{P
for(int i=0;i<nStartPos.length;i++) }ACg#;>/+
fileSplitterFetch.splitterStop(); X,+a 6F
qQ]fM$!
~m<K5K6 V
} (t3gNin
} H.iCYD_=
//负责部分文件的抓取 >A@yF?
**FileSplitterFetch.java 8Ckd.HKpQ
*/ +a,#BSt
package NetFox; dpE^BWv3
Hc8^w6S1@
82 |^o
import java.io.*; &bJBsd@Os
import java.net.*; R%r25_8
eb}XooX
q'7.lrKwa>
public class FileSplitterFetch extends Thread { f%n ;Z}=
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}>AA[ba"'
String sURL; //File URL |8{ k,!P'K
long nStartPos; //File Snippet Start Position v(0ujfSR0
long nEndPos; //File Snippet End Position au19Q*r9
int nThreadID; //Thread's ID cg^~P-i@*
boolean bDownOver = false; //Downing is over "4xo,JUf
boolean bStop = false; //Stop identical .= ~2"P
FileAccessI fileAccessI = null; //File Access interface ).GM0-y
TR*vZzoy
lE%KzX?&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H/`@6, j
{ A-m IWTa
this.sURL = sURL; o_=4Ex "
this.nStartPos = nStart; @Oz3A<M
this.nEndPos = nEnd; NApy(e5%
nThreadID = id; 19[oXyFI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _l] 0V g`
} D]fgBW-
.nEMd/pX
fzVN;h
public void run() Muq~p~m}
{ WU=EJY}#n
while(nStartPos < nEndPos && !bStop) ;Q&9t
{ :''Swi<H
pRlScD_};
s\~j,$Mm2
try{ .KG9YGL#
URL url = new URL(sURL); cV1E<CM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2s,cyCw&
httpConnection.setRequestProperty("User-Agent","NetFox"); e/x 9@1s#
String sProperty = "bytes="+nStartPos+"-"; #F3'<(j
httpConnection.setRequestProperty("RANGE",sProperty); <i]-.>&J
Utility.log(sProperty); s^6,"C
2N |iOog
ODKh/u_
InputStream input = httpConnection.getInputStream(); +8"8s
//logResponseHead(httpConnection); tUJe-3,
R-W.$-rF
r/':^Ex
byte[] b = new byte[1024]; ,hJx3g5#n
int nRead; WoNJF6=?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JXww_e[
{ HD{u#~8{
nStartPos += fileAccessI.write(b,0,nRead); 3&E@#I^],
//if(nThreadID == 1) IDF0nx]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); . WJ
} Q~Nq5[
R$IsP,Uw
e\aW~zs2
Utility.log("Thread " + nThreadID + " is over!"); ;B2&#kot7
bDownOver = true; 0H%zkJ>Q
//nPos = fileAccessI.write (b,0,nRead); ro?.w
} Zw4%L?
catch(Exception e){e.printStackTrace ();} pHoxw|'Y
} FeZWS>N
} )#4(4 @R h
jC:D>
N0$ uB"
//打印回应的头信息 z*b|N45O
public void logResponseHead(HttpURLConnection con) wZCboQ,
{ Fsq)co
for(int i=1;;i++) 9X1vL
{ c*axw%Us
String header=con.getHeaderFieldKey(i); h7.jWJTo
if(header!=null) 8?'=Aeo
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;){ZM,Ox
Utility.log(header+" : "+con.getHeaderField(header)); ]fh(b)8_,
else I5[@C<b
break; Je"XIhBr
} :qR8 e J
} dR>$vbjh1Z
|FaK=e
j5n"LC+oz
public void splitterStop() s)3CosU
{ o,_F;ZhE
bStop = true; WFFd3TN%<
} pcOKC0b.
ZF#lh]
e{4e<hd
} d6m&nj
1W0[|Hf2v*
;*nzb!u\\
/* DH$Nz
**FileAccess.java K'Wv$[~Dc
*//文件访问(定位，写) Z3Ww@&bU
package NetFox; .!2 u#A
import java.io.*; RvU'8Y?>w
/IX555/dR1
pFu!$.Fr
public class FileAccessI implements Serializable{ JAMV@
=SW<Vhtb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %@aC5^Ovy+
RandomAccessFile oSavedFile; Wy1.nn[
long nPos; Kn?h
m,6u+Z,
.A/xH x
public FileAccessI() throws IOException 8{icY|:MTN
{ .DnG}884
this("",0); cFjD*r-
} zw5Ol%JF
A'u]z\&%c
-m=!SQ >9
public FileAccessI(String sName,long nPos) throws IOException aAd1[?&
{ KG(l=? N
oSavedFile = new RandomAccessFile(sName,"rw"); ,N_V(Cx5pt
this.nPos = nPos; !w!k0z]
oSavedFile.seek(nPos); %bdBg
} _D+J3d(Pjk
DV({! [EP
`4Z:qh+fJ
public synchronized int write(byte[] b,int nStart,int nLen) NVom6K
{ z}r
int n = -1; z^/9YzA!6
try{ Lcy6G%A
oSavedFile.write(b,nStart,nLen); Sy*p6DP
n = nLen; j,i)ecZ>
} DbR!s1ux
catch(IOException e) <ZO+e*4
{ FKf2Q&2I
e.printStackTrace (); :UKc:JVNM
} 6RSit
ZRr.kN+F
YoQQ ,
return n; mZ?QtyljT
} vQoZk,
7a/ BS(kq<
&u<%%b|
} d?/g5[
J-klpr#
R$eEW"]
/* 7coVl$_Zl
**SiteInfoBean.java zqXDD; w3
*/ r#}o +3*
package NetFox; = ~*Vfx
O ~[[JAi[
_3g!_
public class SiteInfoBean { "-IF_Hid
.%0a
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private String sSiteURL; //Site's URL NQOf\.#g
private String sFilePath; //Saved File's Path (\ |Go-2G
private String sFileName; //Saved File's Name rof9Rxxe-
private int nSplitter; //Count of Splited Downloading File ME5M;bz(
PyQ\O*
d7Cs a c
public SiteInfoBean() c[vFh0s"m
{//nSplitter的缺省值为5 BryD?/}P)M
//default value of nSplitter is 5 J'&K
this("","","",5); 4^ 0CHy
} !Ap*PL
!"F8jA}
urL@SeV+$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PVQn$-aq1
{ EyV5FWb58
sSiteURL= sURL; &-vHb
sFilePath = sPath; YQ1rS X3
sFileName = sName; %r(qQM.Pl
this.nSplitter = nSpiltter; SapVS*yx@
vZqW,GDfXo
cwHbm%
} :pvVm>
]%G#x
[KW)z#`*
public String getSSiteURL() e?GzvM'2
{ ^>fr+3a"P
return sSiteURL; x%dVD
} eQfXUpk3@I
T&<ee|t@{
,RAP_I!_x
public void setSSiteURL(String value) a]8W32
{ w`/~y
sSiteURL = value; szOa yAS
} J0t_wMJa
*~UK5Brf1
z4]z3U<}3]
public String getSFilePath() AZ\f6r{
{ J'wJe,
return sFilePath; $9G".T
} d]?fL&jr
0yb9R/3.
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public void setSFilePath(String value) --vJR/-
{ +5:9?&lH
sFilePath = value; }JUc!cH8z
} ,OkI0[
GN+,9
iqWkhJphv
public String getSFileName() _Qb].~
{ lI9|"^n7F
return sFileName; vcP_gJz
} 7VLn$q]:
+Q:)zE
R0GD9
public void setSFileName(String value) '^'PdB
{ #A< |qd
sFileName = value; LZJFp@
} ,K.Wni#m
&5%~Qw..
+N|t:8qaf
public int getNSplitter() ndvt $*
{ AFsYP/g]
return nSplitter; MJn=
} %^u e
^>y|{;`
\rH0=~F-P
public void setNSplitter(int nCount) aMxM3"
{ ABq#I'H#@2
nSplitter = nCount; :{-/b
} uPb.uG
} r;"Qu
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}AS3]Lub@
/* Bv7os3xb
**Utility.java bhW&,"$Z
*/ <^e
package NetFox; +rDKx(Rk
kr44@!s+'
FJsM3|{2=d
public class Utility { QghL=
H 9?txNea
Jg6@)<n
public Utility() D@ BP<
{ i\ )$
b,#?LdQ%
cfc=a
} Ece=loV*l
hz-^9U
//线程睡眠 U@LIw6B!KL
public static void sleep(int nSecond) iu`B8yI
{ 87R$Y> V
try{ =o[H2o y
Thread.sleep(nSecond); {t('`z
} oe=W}y_k
catch(Exception e) suN}6CI
{ uLt31G()
e.printStackTrace (); -]:1zU
} `I(5Aj"
} l~x 6R~q
E/C3t2@-
//日志 \"+}-!wr
public static void log(String sMsg) 8?hj}}H
{ YG#{/;^nm)
System.err.println(sMsg); Mw6 Mt
} M1K[6V!
=BeJ.8$@VC
6PLdzZ{
public static void log(int sMsg) Fw%S%*B8g
{ e#ne5
System.err.println(sMsg); 1@q"rPE^
} fs,>X!l+
} !*,m=*[3
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E$4Ik.k
/* wqJ1^>TB
**TestMethod.java i >BQRbU
*/ p'=XW#2 >
package NetFox; R1Q~UX]d=
+ ;B K|([#
F^cu!-L
public class TestMethod { 41i#w;ojI
OB+QVYk"
J/c5)IB|
public TestMethod() .R&jRtb/E
{ ///xx/weblogic60b2_win.exe n-CFB:L
try{ Z07SK 'U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |bk$VT4\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =qww|B92
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9y;zk$O8
fileFetch.start(); jjg[v""3|
} "X-"uIc
catch(Exception e){e.printStackTrace ();} 4z^VwKH\j
&C6*"JZ4
S|_"~Nd=
} c,5yH
-D wO*f
Ots]y
public static void main(String[] args) S\6.vw!'
{ 8q|T`ac+N
new TestMethod(); +VO(6Jn
} %}Z1KiRiX
} |N5|B Q(y$
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