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)); ,JPDPI/a
} WE-+WC!!:
for(int i=0;i<nEndPos.length-1;i++) -B-HZ_
{ 1W}k>t8?h'
nEndPos = nStartPos[i+1]; 7;?7q
} O~6AX)|&=
nEndPos[nEndPos.length-1] = nFileLength; u9]M3>
} ??++0<75
} Lw?>1rTT/
t_(Se
&b2@+/ F
//启动子线程 /1=x8Sb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q^?$2ck=
for(int i=0;i<nStartPos.length;i++) |O"Pb`V+
{ %L-{4Z!"sI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (dV7N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %0 U@k!lP
nStartPos,nEndPos,i); [DTe
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %Rk0sfLvn
fileSplitterFetch.start(); 7~QAprwVS
} <\d2)Iv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -;i:bE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :&E~~EUW
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gxC`Ml
nEndPos = " + nFileLength); #ZHKq7
// fileSplitterFetch[nPos.length-1].start(); sp0_f;bC
cwQ*P$n
'}F9f?
//等待子线程结束 M[_Ptqjb
//int count = 0; @9k/od@mW
//是否结束while循环 2{g&9
boolean breakWhile = false; vJ&35nF&
\oP
$ylxl"Y
while(!bStop) (;HO3Z".q$
{ )k `+9}OO
write_nPos(); V{}TG]
Utility.sleep(500); F0kQ/x
breakWhile = true; gDX\ p>7
>9<rc[
XqcNFSo)
for(int i=0;i<nStartPos.length;i++) Jr>Nc}!U
{ ^{E_fQJX
if(!fileSplitterFetch.bDownOver) f uH3C~u7<
{ nGTqW/k[+s
breakWhile = false; 90H/Txq
break; wvr`~e
} |I.5]r-EK
} GB6(WAmr
if(breakWhile) +>%AG&Pc
break; 'sk M$jr
;b_<5S
vgr5j
//count++; \,I{*!hw
//if(count>4) a3He-76
// siteStop(); Q"oJhxS
} %r:4'$E7|
KkR.p,/
Lk-h AN{[
System.err.println("文件下载结束！"); }F3}"Ik'L
} +]Z*_?j9{
catch(Exception e){e.printStackTrace ();} t Q>/1
} ~6OdwGWV
owO&[D/
p\]rxtm
//获得文件长度 1}CJ&
public long getFileSize() SNHALF
{ P>|sCF
int nFileLength = -1; ~k ]$J|}za
try{ 8,B#W#*{
URL url = new URL(siteInfoBean.getSSiteURL()); G/KTF2wl7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~BXy)IB6
httpConnection.setRequestProperty("User-Agent","NetFox"); ?.nD!S@
@,pn/[
H\|H]:CE
int responseCode=httpConnection.getResponseCode(); Jb8%A@Z+
if(responseCode>=400) Q:Y`^jP
{ "m}N hoD4
processErrorCode(responseCode); m`@~ZIa?>B
return -2; //-2 represent access is error ',6d0>4*
} xQqZi b5I
G4uOY?0N
48mTL+*
String sHeader; rFto1m
miY=xwK&
EDA6b]
for(int i=1;;i++) b|Eo\l2
{ 3E8 Gh>J_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t0T#Xb
//Utility.log(in.readLine()); }&EdA;/o_
sHeader=httpConnection.getHeaderFieldKey(i); uN$ <7KB"
if(sHeader!=null) qp/nWGj
{ P_ b8_ydU
if(sHeader.equals("Content-Length")) :IozWPs*
{ (%{!TJgZR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >5Sm.7}R
break; Q1DiEg
} IXR%IggJA
} jZqCM{
else \YH*x`
break; w|ct="MG
} XBTjb
} _+&/P&
catch(IOException e){e.printStackTrace ();} QEY#U|
catch(Exception e){e.printStackTrace ();} byIP]7Ld
{\ BFWGX
"s\himoa
Utility.log(nFileLength); Lo +H&-
G-DOI
s09&A]G
return nFileLength; ESkhCDU
} [iN\R+:
kg$w<C@#"
sg_%=;
//保存下载信息（文件指针位置） 9]a!1
private void write_nPos() 0}$R4<"{Y>
{ H$xUOqL
try{ =K9-
output = new DataOutputStream(new FileOutputStream(tmpFile)); S$nEflcz
output.writeInt(nStartPos.length); -qB{TA-.\
for(int i=0;i<nStartPos.length;i++) W)u9VbPk[
{ }DkdF
// output.writeLong(nPos); fvoPV&:
output.writeLong(fileSplitterFetch.nStartPos); WAGU|t#."
output.writeLong(fileSplitterFetch.nEndPos); ET~^P
} E,|OMK#
output.close(); F^7qr
} s&6/fa
catch(IOException e){e.printStackTrace ();} G}'\
catch(Exception e){e.printStackTrace ();} nD{{/_"'
} 3O?[Yhk`.
51!#m|
<+ckE2j
//读取保存的下载信息（文件指针位置） 5Ja[p~^L
private void read_nPos() G2FD'Sf
{ 2L7ogyrU/A
try{ -qDL':
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^W[3RiG
int nCount = input.readInt(); `q?@ Ob&
nStartPos = new long[nCount]; sq}uq![?M
nEndPos = new long[nCount]; ]hY4 MS
for(int i=0;i<nStartPos.length;i++) WNiM&iU
{ W%K=N-kE_
nStartPos = input.readLong(); ?qczMck_
nEndPos = input.readLong(); |Q#CQz
} 6b h.5|
input.close(); e|.a%,Dcy
} +Pb@@C&
catch(IOException e){e.printStackTrace ();} l gTw>r
catch(Exception e){e.printStackTrace ();} n`|CDKb
} Kl*/{&,P
WVh]<?GWXk
7iH%1f
private void processErrorCode(int nErrorCode) gnZc`)z
{ #80r?,q
System.err.println("Error Code : " + nErrorCode); A{\!nq_~N
} UAtdRVi]M
r-c1_ [Q#
[J43]
//停止文件下载 Zex`n:Wl?j
public void siteStop() nbU?:=P
{ >2LlBLQ
bStop = true; Trml?zexD
for(int i=0;i<nStartPos.length;i++) :&$WWv
fileSplitterFetch.splitterStop(); )<^G]ajn
gqACIXR
3qwSm<
} _S6SCSFc
} L7$1rO<
//负责部分文件的抓取 2<^eVpNJR
**FileSplitterFetch.java cK1RmL"3
*/ cAzlkh
package NetFox; MF4B 2d
r$;u4FR
MK, $#
import java.io.*; DVjsz
import java.net.*; _SQ0`=+
X6EnC57
5@{~830
public class FileSplitterFetch extends Thread { KvuM{UI5
B7nm7[V
Ct9*T`Gl
String sURL; //File URL j79$/ Ol
long nStartPos; //File Snippet Start Position C: a</Sl
long nEndPos; //File Snippet End Position t3;QF
int nThreadID; //Thread's ID Hp-vBoEk
boolean bDownOver = false; //Downing is over hrTl:\
boolean bStop = false; //Stop identical @z7$1pl}
FileAccessI fileAccessI = null; //File Access interface <|4L+?_(&
#^bn~
ZTK)N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Oftjm X_
{ 8DZ OPA
this.sURL = sURL; h>&t``<
this.nStartPos = nStart; %jj\w>
this.nEndPos = nEnd; H.[t&VO
nThreadID = id; @ R;o $n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3+WostOx
} !i?aRI/6
Xm[Cgt_?
Y .\<P*iO
public void run() d0N/!;
{ H4g1@[{|0O
while(nStartPos < nEndPos && !bStop) 1_G5uHO
{ zZ{(7Kfz
_:?b-44
jMQ7^(9-
try{ #%SF2PB;
URL url = new URL(sURL); $O^U"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6ragRS/'x
httpConnection.setRequestProperty("User-Agent","NetFox"); G0pqiU6
String sProperty = "bytes="+nStartPos+"-"; A=pyaU`aE
httpConnection.setRequestProperty("RANGE",sProperty); TvwkeOS#}7
Utility.log(sProperty); qM:*!Aq0g
;&]oV`Ib
z%Ivc*x5
InputStream input = httpConnection.getInputStream(); UViWejA/*u
//logResponseHead(httpConnection); Ln&CB!u
#F6!x3Z
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byte[] b = new byte[1024]; I8{ohFFo
int nRead; |NXe{q7{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ='\E+*[$I
{ .*g^ i`
nStartPos += fileAccessI.write(b,0,nRead); *|&&3&7
//if(nThreadID == 1) o9AwW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WO"<s{v
} V?o%0V
+"Mlj$O
OK=ANQjs(
Utility.log("Thread " + nThreadID + " is over!"); P/doNv}iG
bDownOver = true; zc%HBZ3p
//nPos = fileAccessI.write (b,0,nRead); F`JW&r\
} qJT|om LY
catch(Exception e){e.printStackTrace ();} -)Y[t Z^*`
} Dh B*k<S
} H(F9&6}
&=hkB9 ;
7xjihl3
//打印回应的头信息 n%={!WD
public void logResponseHead(HttpURLConnection con) s!\Gi5b
{ R)BH:wg"
for(int i=1;;i++) -{s9PZ3~_
{ XT~]pOE;D
String header=con.getHeaderFieldKey(i); ~mYCXfoc{
if(header!=null) %n:ymc $}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nTxN>?l2E
Utility.log(header+" : "+con.getHeaderField(header)); 53)*i\9&
else Lo^gg#o
break; <%EjrjdvL+
} C+X-Cp
} 6eHw\$/
EGJrnz8
m005*>IY
public void splitterStop() /faP@Q3kR
{ y`p(}X`>
bStop = true; &U0Y#11Cx
} 5qQ\H}
F@Cxjz
"IKbb7x
} C#D8 E.W
anxwK47
Lt\=E8&rh
/* OZi4S3k
**FileAccess.java K:8. Dvn
*//文件访问(定位，写) `*HM5 1U
package NetFox; (`FY{]Wz!
import java.io.*; - {|
&Y|AX2KUC
dn|OY.`|
public class FileAccessI implements Serializable{ NGOyd1$7N
G=qT{c8Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tboc7Hor4
RandomAccessFile oSavedFile; |g8Q.*"l[
long nPos; A<<Bm M.%
1n|K
$qyST
public FileAccessI() throws IOException f,QBj{M,
{ +a!uS0fIJi
this("",0); co [
} Onj)AJ9M0r
mUjM5ceAXO
o`}(1$a>
public FileAccessI(String sName,long nPos) throws IOException Trt1M
{ $J)2E g
oSavedFile = new RandomAccessFile(sName,"rw"); O>kM2xw
this.nPos = nPos; 0rj50$~$]
oSavedFile.seek(nPos); Xhm)K3RA*T
} RoeLf Ow
e{7"7wn=
4&+lc*
public synchronized int write(byte[] b,int nStart,int nLen) `/L D:R
{ TwLQ;Q
int n = -1; 7bC)Co#:
try{ _"c:Z!L
oSavedFile.write(b,nStart,nLen); ".Sa[A;~
n = nLen; 1]]#HTwX
} i :Sih"=
catch(IOException e) Nvj0MD{ X
{ rX@?~(^ML
e.printStackTrace (); Spt;m0W90
} +W[NgUrGJ
mr\C
[3fmhc
return n; ]Wdnr1d~8
} r>3y87
bbxo!K m"
4oA9|}<FR
} 66%4p%#b4
Xgyi}~AoaU
- j_
/* Z]x)d|3;
**SiteInfoBean.java gL}x|Q2`
*/ 1_0\_|
package NetFox; Lc5I?}:;L
g]Fm%iy
ypV>*
public class SiteInfoBean { i*2l4
x>m=n_
b?deZ2"L#
private String sSiteURL; //Site's URL q"|#KT^)
private String sFilePath; //Saved File's Path UTph(U#
private String sFileName; //Saved File's Name )9'Zb`n
private int nSplitter; //Count of Splited Downloading File N,~"8YSo
I!;vy/r
f5dctDHP
public SiteInfoBean() +L\bg|;
{//nSplitter的缺省值为5 URb
//default value of nSplitter is 5 <Pg<F[eDM
this("","","",5); IBSoAL
} I4%25=0?
z)0%gd|
Z|IFT1K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Sxg&73;ZV
{ fOkB|E]
sSiteURL= sURL; #xTu {
sFilePath = sPath; ->Bx>Y
sFileName = sName; CyEEE2cV
this.nSplitter = nSpiltter; G;Thz
+U= !svE
5x1_rjP$|
} kV:C=MLI
2z615?2_U
ti}G/*4
public String getSSiteURL() F}dq~QCzw
{ k%fy
return sSiteURL; JBxizJBP
} ga+Z6|t
%x zgTZ
IWD21lS
public void setSSiteURL(String value) H]d'#1G
{ k=8LhO
sSiteURL = value; SdOE^_@:
} ?7CHHk
sksop4gu5
U**v'%{s
public String getSFilePath() 5'hQ6i8
{ jFThW N
return sFilePath; >h<bYk"9Q
} .vJt&@NO
\QKr2|
JU\wvP5j
public void setSFilePath(String value) Q1(6U6L
{ J~URv)g
sFilePath = value; @mu2,%
} <<:a>)6\
e+=IGYC
>iIUS
public String getSFileName() ":upo/xN
{ [d~25
return sFileName; Y%iimbBY|
} BpQ/$?5E"
875BD U
'#faNVPABh
public void setSFileName(String value) 7gY^aMW
{ d[Lr`=L;
sFileName = value; Ul?92
} %B{NH~
&?@5G
wBK%=7
public int getNSplitter() uRu)iBd D
{ M$Of.
return nSplitter; )-4xI4
} ;4rTm@6
!j|93*
HD95>%
public void setNSplitter(int nCount) _2C[F~ +l
{ 2AZ)|dM'`
nSplitter = nCount; G,J~Ed
} zrJ/Fs+s
} |vY0[#E8&
d|8iD`sZz
1~#2AdG
/* 6Wabw:
**Utility.java aj:B+}1
*/ P,[O32i#
package NetFox; 0u'qu2mV
C'c9AoE5>
$MT'ZM
public class Utility { xXktMlI
iS"(
NHCdf*
public Utility() k'K&GF1B
{ AShnCL8uR
!L#>wlX)
R""P01IZH
} ]$>O--
6DFF:wrm&
//线程睡眠 TFWx(}1
public static void sleep(int nSecond) vNhi5EU
{ O,kzU,zOs
try{ %`P6a38j
Thread.sleep(nSecond); bJo)rM:m
} ZgcJxWC<
catch(Exception e) \P;%fN
{ dT%$"sj5
e.printStackTrace (); fq.ui3lP)
} `;ofQz4
} GN4'LU
N;9m&)@JR'
//日志 ) /kf
public static void log(String sMsg) G $TLWfm
{ GnlP#;
System.err.println(sMsg); P9)E1]Dc$
} )")_aA
>xU$)uE&
)x/Spb
public static void log(int sMsg) UJXRL
{ p9;Oe,Il
System.err.println(sMsg); ,m-z D
} ?mJNzHrq;
} cuO)cj]@e
,&$+{3
WB2An7i@"{
/* IcM99'P(
**TestMethod.java L7*,v5
*/ R^PPgE6!$
package NetFox; gAA2S5th
8,Jjv*
Une,Y4{u
public class TestMethod { gBzg'Z
.Vm!Ng )j
sw.cw}1
public TestMethod() L> ehL(]!
{ ///xx/weblogic60b2_win.exe uES|jU{]b
try{ *OOi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +/tNd2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $niJw@zC
SiteFileFetch fileFetch = new SiteFileFetch(bean); '~HCYE:5
fileFetch.start(); 7~@9=e8G
} #V[j Q Vl
catch(Exception e){e.printStackTrace ();} d{cd+An
}pJ6CW
3BuG_ild
} _d#1muZ?p|
WgxGx`Y)
'?Mt*%J@=$
public static void main(String[] args) poZ04Uxo>
{ zW^_w&fd^j
new TestMethod(); ^gb3DNV~y
} G_GV
} [?3]+xr:
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