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)); QTmMj@R&(
} k8S`44vj
for(int i=0;i<nEndPos.length-1;i++) Dwa.ZY}-
{ Q*W$!ZUT
nEndPos = nStartPos[i+1]; ur| vh5
} 2SRmh!hr
nEndPos[nEndPos.length-1] = nFileLength; l\"wdS}
} ,1e\}^
} "x4}FQ
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$X ]t}=
//启动子线程 {osadXdC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uMb[0-5
for(int i=0;i<nStartPos.length;i++) >mUSRf4
{ lDVw2J'p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }Q-%ij2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^tRy6zG
nStartPos,nEndPos,i); J_}Rsp ED
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iVZX
fileSplitterFetch.start(); o!Y61S(
} \L:+k `
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Sh;Z\nj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u_'XUJ32!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )tp;2rJ/
nEndPos = " + nFileLength); 3\Tqs
// fileSplitterFetch[nPos.length-1].start(); {D`_q|
s#4Q?<65u
%j. *YvveW
//等待子线程结束 g..&x]aS(
//int count = 0; qE@H~&
//是否结束while循环 -40s
boolean breakWhile = false; ::k cV'*
9w}_CCj3
X(qs]:
while(!bStop) rvG0aqO`
{ N+CcWs!E
write_nPos(); |gwGCa+
Utility.sleep(500); >)8<d3m
breakWhile = true; 4#&w-W
N D1'XCN
^<`uyY))Q
for(int i=0;i<nStartPos.length;i++) 5]F4.sa
{ HzZ.q2Zz%
if(!fileSplitterFetch.bDownOver) +Cs.v.GA5
{ >goG\y
breakWhile = false; 9ohO-t$XkY
break; vhz Q.>
} %h4|$
} 1pJ?YV
if(breakWhile) 5$%CRm
break; ~zcB@; :
CJf4b:SY@
jVInTR0f[
//count++; n|Gw?@CU7
//if(count>4) &]jCoBj+_
// siteStop(); w|( ix;pK
} .,&6 x.
IiZXIG4H
>d<tcaB
System.err.println("文件下载结束！"); <hB~|a<#
} 9HG"}CGZP
catch(Exception e){e.printStackTrace ();} l*]nvd_
} 3}x6IM2
RWdx)qj{
^KjxQO6y3
//获得文件长度 o!sHK9hvJ)
public long getFileSize() TSKR~3D#
{ 4mwLlYZ
int nFileLength = -1; 5@yBUwMSj
try{ >e^8fpgSo
URL url = new URL(siteInfoBean.getSSiteURL()); ,.TwM;w=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #)z7&nD
httpConnection.setRequestProperty("User-Agent","NetFox"); fk'DJf[M
Q|tzA10E
}ZkGH}K_}
int responseCode=httpConnection.getResponseCode(); 7f\/cS^
if(responseCode>=400) o>MB8[r
{ /[=U$=uH
processErrorCode(responseCode); m?]= =9
return -2; //-2 represent access is error drd5oZ
} uYMH5Om+i
8c'5P
R/ 3#(5
String sHeader; H':0
Oi$$vjs2
C`b)}dY
for(int i=1;;i++) gM_MK8py
{ }-%:!*bLj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i?IV"*Ob1N
//Utility.log(in.readLine()); .(X!*J]G
sHeader=httpConnection.getHeaderFieldKey(i); Mq4>Mu
if(sHeader!=null) t[%ELHV
{ g#r,u5<*?
if(sHeader.equals("Content-Length")) ~vstuRRST
{ eGi|S'L'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ep8 y
break; MURHv3
} o{xA{ @<
} FcmL4^s.`
else X,ok3c4X
break; v\Edf;(
} P;[>TCs ]8
} ?Y'r=Q{w
catch(IOException e){e.printStackTrace ();} Na{&aqdz
catch(Exception e){e.printStackTrace ();} K?H(jP2mpM
l4Qv$
V2BsvR`
Utility.log(nFileLength); 2X|nPhNi
],w+4;+
m}GEx)Y D
return nFileLength; 0JX/@LNg0
} u!9bhL`
Ctpc]lJ}
u#`'|ko\9
//保存下载信息（文件指针位置） jU_#-<'r
private void write_nPos() L;'C5#GN
{ 1j\wvPLr
try{ =801nZJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); S'(Hl}h!.
output.writeInt(nStartPos.length); @+(a{%~7y
for(int i=0;i<nStartPos.length;i++) :AM_C^j~ D
{ apd"p{
// output.writeLong(nPos); 5gH'CzU?
output.writeLong(fileSplitterFetch.nStartPos); {14sI*b16
output.writeLong(fileSplitterFetch.nEndPos); CV7%ud]E
} [Ontip
output.close(); u\P)x~-TM
} y];@ M<<?e
catch(IOException e){e.printStackTrace ();} ^ Mw=!n[
catch(Exception e){e.printStackTrace ();} '~OKt`SfIo
} :?z E@Ct
#PZBh
kYU!6t1
//读取保存的下载信息（文件指针位置） TTm
private void read_nPos() uoe>T:
{ T[]kun
try{ mBWhC<kKs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <7yn:
int nCount = input.readInt(); sZYTpZgW4L
nStartPos = new long[nCount]; Ng+Ge5C9
nEndPos = new long[nCount]; i=j4Wg,{J
for(int i=0;i<nStartPos.length;i++) .p /VRlLU
{ +e( (!
nStartPos = input.readLong(); `]m/za%7
nEndPos = input.readLong(); =*Y=u6?
} H`Ld,E2ex&
input.close(); r:9H>4m
} ]-tAgNzl%
catch(IOException e){e.printStackTrace ();} Cswa5l`af
catch(Exception e){e.printStackTrace ();} @ )m9#F
} l527>7 eT
iYl$25k/1
@d_;p<\l
private void processErrorCode(int nErrorCode) V9<CeTl'
{ (]*!`(_b
System.err.println("Error Code : " + nErrorCode); 2Wq/_:
} u}BN)%`B
31n|ScXv
eKek~U&
//停止文件下载 "i/3m'<2
public void siteStop() s&~.";b
{ d&5GkD.P
bStop = true; B)L;ja
for(int i=0;i<nStartPos.length;i++) Dd$CN&Ca
fileSplitterFetch.splitterStop(); Oky9GC.a
0fU^
X]AbBzy
} } P/ x@N
} "Go)t+-
//负责部分文件的抓取 %QKRl5RM-
**FileSplitterFetch.java "f3KE=cUm
*/ jj*e.t:F
package NetFox; 7COJ.rA
Mv^G%zg2
i=8){GX4
import java.io.*; V0'_PR@;
import java.net.*; LTt|"D
{qkd63X
o=N_0.
public class FileSplitterFetch extends Thread { y6!Zt}m
txW<r8
.3*VkAs
String sURL; //File URL 0A>Fl*
long nStartPos; //File Snippet Start Position 7+^4v(s
long nEndPos; //File Snippet End Position b1`(f"&l
int nThreadID; //Thread's ID 4<QSot
boolean bDownOver = false; //Downing is over lg!{?xM
boolean bStop = false; //Stop identical Pw_[{LL
FileAccessI fileAccessI = null; //File Access interface O`W&`B(*k
j2"Y{6c
b(McH*_8e
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zPT!Fa`
{ %xWscA%^u
this.sURL = sURL; mQ]wLPP{1
this.nStartPos = nStart; L?(% *
this.nEndPos = nEnd; k1
nThreadID = id; IfGQeynj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .+TriPL
} 9QryW\6.@z
Sk 10"DB/
Z/@%MEU[zl
public void run() (" +/ :
{ C6`<SW
while(nStartPos < nEndPos && !bStop) $k&}{c8P
{ l TJqWSV=f
%<Q?|}
Bz#K_S
try{ 63?fn~0\
URL url = new URL(sURL); %7oB[2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $@blP<I
httpConnection.setRequestProperty("User-Agent","NetFox"); 2o5v{W
String sProperty = "bytes="+nStartPos+"-"; uKZe"wN;
httpConnection.setRequestProperty("RANGE",sProperty); #Ua+P(1q
Utility.log(sProperty); ,lly=OhKb
{%;KkC8=R
jW-j+WGSM
InputStream input = httpConnection.getInputStream(); (SlrV8;
//logResponseHead(httpConnection); gB?~!J?
~CB6+t>
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byte[] b = new byte[1024]; Eb<iR)e H=
int nRead; = ?hx+-'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]8XY"2b
{ vQ}'4i8(
nStartPos += fileAccessI.write(b,0,nRead); fYzOT,c
//if(nThreadID == 1) yEfV8aY'*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |,ZmRW^2K
} {m/\AG)1I
hL,+wJ+A
D~xUr)E
Utility.log("Thread " + nThreadID + " is over!"); NgnHo\)
bDownOver = true; Svmyg]
//nPos = fileAccessI.write (b,0,nRead); T$'GFA
} ?wR;"
catch(Exception e){e.printStackTrace ();} wxg`[c$:
} RJ_ratKN*g
} <(Wa8PY2(
MKdBqnM(F
ZN2g(
//打印回应的头信息 t_q`wKDE
public void logResponseHead(HttpURLConnection con) nJ|8#U7
{ %8T:rS
for(int i=1;;i++) {daNw>TH
{ h !~u9
String header=con.getHeaderFieldKey(i); O]n"aAu@
if(header!=null) qYW{$K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =Po!\[SBU
Utility.log(header+" : "+con.getHeaderField(header)); OKp(A
else sM?bUg0w
break; 1a)NM#
} kQ$Q}3f
} :ji_dQ8k
8IH&=3
gkuI!=
public void splitterStop() Mc9P(5Bf
{ <)zh2UI
bStop = true; B(mxW8y
} EO,;^RtB
A`7uw|uO$
'r%`(Z{~
} daaEN(
QY2!.a^q
0:**uion
/* :XMw="u=
**FileAccess.java aho;HM$hjP
*//文件访问(定位，写) u!%]?MSc
package NetFox; )Xa`LG=|
import java.io.*; 6-#f1D 6
qoMYiF}/e
yg "u^*r&
public class FileAccessI implements Serializable{ e:V(kzAY;
^\cB&<h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r+;C}[E
RandomAccessFile oSavedFile; jz|zq\Eek
long nPos; ' %OQd?MhL
}VE[W
O!zH5
public FileAccessI() throws IOException e+=Ojo#
{ kRskeMr:Rd
this("",0); qqSk*oH~
} T IPb ]
uG3t%CmN
A0M)*9 f
public FileAccessI(String sName,long nPos) throws IOException xkOyj`IS
{ o:#MP(h,N
oSavedFile = new RandomAccessFile(sName,"rw"); /MSz{ %v
this.nPos = nPos; {t[j>_MYw
oSavedFile.seek(nPos); ?N#mD
} ]}F_nc2L
Tn/ 3`j {
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public synchronized int write(byte[] b,int nStart,int nLen) -) $$4<L
{ =4yME
int n = -1; d> Y9g
try{ au574tj
oSavedFile.write(b,nStart,nLen); :n>m">4
n = nLen; XN]kNJX
} :SSe0ZZ_6b
catch(IOException e) B{QY-F~
{ p0uQ>[NV0
e.printStackTrace (); 0<Px2/
} @g""*T1:$
v%V$@MF
^o|igyS9
return n; /bVU^vo
} TH)gW
G F,/<R#
G[6V=G
} ?`,UW;Br6
iO3@2J
Tm[IOuhM'?
/* " 9 h]P^
**SiteInfoBean.java eqs.zL
*/ O} QTg
package NetFox; +=Crfvt
Q9X_aB0
GKtG#jZ&
public class SiteInfoBean { {k}S!T
<"AP&J'H
F^&_O*"
private String sSiteURL; //Site's URL ,S:LhgSP
private String sFilePath; //Saved File's Path 0NZg[>H
private String sFileName; //Saved File's Name hI;tB6
private int nSplitter; //Count of Splited Downloading File {?l#*XH;
`*8p T
4&r^mGs,
public SiteInfoBean() o{?s\)aBa
{//nSplitter的缺省值为5 DK&J"0jz,
//default value of nSplitter is 5 LnxJFc:1K
this("","","",5); Wze\z
} CP'?Om2
%ztCcgu*
JpD<2Mz_|V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lzfaW-nu
{ zOCru2/
sSiteURL= sURL; }X)mZyM[
sFilePath = sPath; i=.zkIjSh
sFileName = sName; Cz+>S3v M
this.nSplitter = nSpiltter; 8"LvkN/v^
:u`
\$V~kgQ0
} z(aei(U=
y0M^oLx
5"c#OU
public String getSSiteURL() :U0z;
{ eFp4MD8?
return sSiteURL; BE:HO^-.1
} :o&qJ%
5K;jW
~0!s5
public void setSSiteURL(String value) bB->\
{ TV#pUQ3K
sSiteURL = value; g03I<<|@
} F# y5T3(P
hoD (G X
ZTVX5"#Q
public String getSFilePath() 4W*52*'F,
{ 8{8J(~
return sFilePath; ,mhO\P96ik
} 6OF&Q`*4
ib0M$Y1tIS
-{>JF
public void setSFilePath(String value) u=5&e)v3
{ <6)Ogv",
sFilePath = value; PP.QfY4
} D4ESo)15'
p}.L]Y
ow!utAF
public String getSFileName() xJa
{ 0g,;Yzm
return sFileName; cclx$)X1X
} d0"Hu^]
%]h5\%@w
!<Ma9%uC{
public void setSFileName(String value) 2)Grl;T]s
{ UIi;&[
sFileName = value; Q35$GFj"jD
} Waj6.PCFm
X&8&NkH
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public int getNSplitter() <xKer<D %
{ 3~;LNi
return nSplitter; -uIu-a]
} 3'}(:X(
"9jt2@<
aJ}y|+Cj
public void setNSplitter(int nCount) k(pI5N}pJZ
{ Fo=Icvo
nSplitter = nCount; g'ha7~w(p
} s3>,%8O6
} ]+<[D2f
R?b3G4~
1N{}G$'Go
/* 5 >S#ew
**Utility.java =&;orP
*/ ]B/Gz
package NetFox; c Owa^;
RSC^R}a5
NGcd
public class Utility { SU~t7Ta!G
P$ZIKkf
!K-lO{Z^
public Utility() wmAZ {
{ $A]2Iw!&
18f!k
:W6`{Z
} FNL[6.!PV
`U?" {;j {
//线程睡眠 {VtmQU?cJ
public static void sleep(int nSecond) cVYDO*N2T
{ B+[ri&6X\
try{ M!Q27wT8O
Thread.sleep(nSecond); [-5%[ty9X
} Sio^FOTD
catch(Exception e) 0tyoH3o/d
{ z SDRZ!
e.printStackTrace (); v._Q XcE
} \{``r
} G_vWwH4XtL
Y"6 '
//日志 }K':tX?
public static void log(String sMsg) Q#w mS&$f
{ &YC Z L
System.err.println(sMsg); h_#x@p
} }%Mj`Bh
W^#HR
{9:[nqX
public static void log(int sMsg) ;,2i1m0"
{ v;m`d{(i2
System.err.println(sMsg); o81RD#>E)
} fy]z<SPhVJ
} Bn:"qN~
J<hqF4z
ZeM~13[
/* [d 30mVM
**TestMethod.java Sggha~E2s
*/ omz%:'m`~
package NetFox; =h5&:?X
g~EN3~
7X 4/6]*
public class TestMethod { s8BfOl-
&CBW>*B
cHo@F!{o=
public TestMethod() dpG l
{ ///xx/weblogic60b2_win.exe c=d` DJ
try{ $d0xJxM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cxX/ b,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F{*{f =E!B
SiteFileFetch fileFetch = new SiteFileFetch(bean); pRR1k?
fileFetch.start(); m8M2ka
} =VIU
catch(Exception e){e.printStackTrace ();} stGk*\>U'
?R-4uG[(
bd|ZhRsL
} ox:m;-Ml?_
-c%#Hd
,~8&0p
public static void main(String[] args) 03N|@Tu
{ C_> WU
new TestMethod(); 6=N!()s
} RJ}%pA4I
} X%(1C,C(
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