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)); -)OkG#J@
} B.mbKntK)R
for(int i=0;i<nEndPos.length-1;i++) ]6BmCh
{ *Qg5Z
nEndPos = nStartPos[i+1]; ZE8/ m")
} f;Bfh3
nEndPos[nEndPos.length-1] = nFileLength; .eabtGO,
} Q_kT}6#(J=
} Z0ncN])
=tc`:!$
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//启动子线程 Cj !i)-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <duBwkiG
for(int i=0;i<nStartPos.length;i++) Wz-3?EQ
{ s"=F^#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !0OD(XT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [CDXCV-z
nStartPos,nEndPos,i); hX8gV~E=y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1t[;`iZ
fileSplitterFetch.start(); ` -[Bo
} C^,4`OI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "37@Zt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6A$_&?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gR;8ht(pd(
nEndPos = " + nFileLength); " _:iK]
// fileSplitterFetch[nPos.length-1].start(); +% XhQ
,_Qe}qFU
XewXTd#x
//等待子线程结束 xxoHH#a
//int count = 0; f OM^V{)T
//是否结束while循环 "$W|/vD+
boolean breakWhile = false; f3zfRhkIk
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Db#W/8 a8k
while(!bStop) 4+5OR&kxZ
{ hJ;f1dZ7}
write_nPos(); oEenm\ZI
Utility.sleep(500); Txt%nzIu
breakWhile = true; )l#%.Z9
aYaG]&hb
#a(%(k S
for(int i=0;i<nStartPos.length;i++) pkXfsi-Nu
{ #hgmUa
if(!fileSplitterFetch.bDownOver) H~?*KcZ 0\
{ cuQ7kECV
breakWhile = false; ~m?74^ i
break; ]&C:>
} FDF3zzP0
} Ha)3i{OM
if(breakWhile) "Ju/[#VCJ
break; GUu\dl9WA'
$u; >hk
@V* ju
//count++; ~aJW"\{
//if(count>4) hv$uH7Fz
// siteStop(); Lp:Nw4_
} r~$}G-g
5)d,G9
[$( sUc(%
System.err.println("文件下载结束！"); 4_Qa=T8
} t} *l?$`
catch(Exception e){e.printStackTrace ();} q_<*esZ,
} yu`KzIU
gp~yt0AU
DKy>]Hca
//获得文件长度 c*x J=Gz6d
public long getFileSize() KInUe(g<9M
{ ^&+zA,aL,A
int nFileLength = -1; g08*}0-k
try{ Sf 024
URL url = new URL(siteInfoBean.getSSiteURL()); J3/\<=Qh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [x;(cISK1
httpConnection.setRequestProperty("User-Agent","NetFox"); Rk($lW)
zmrQf/y{R
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int responseCode=httpConnection.getResponseCode(); ,|T*|2Gm
if(responseCode>=400) (3 IZ
{ {S5RK-ax
processErrorCode(responseCode); <|{L[
return -2; //-2 represent access is error = n+q_.A
} %`xV'2H
>_;kTy,
Nb~,`bu,2
String sHeader; w^06z,
\%sPNw=e
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for(int i=1;;i++) DMF?5GX
{ yGba
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :3f-9aRC!
//Utility.log(in.readLine()); S~+O`y^
sHeader=httpConnection.getHeaderFieldKey(i); !]$V9F{K
if(sHeader!=null) UWQtvQ f
{ f{)+-8
if(sHeader.equals("Content-Length")) +7| [b
{ /xl4ohL$a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E%<w5d.lq
break; v<L=!-b^
} ]i-P-9PA4
} y,MPGW_
else <RhOjZgyZ
break; jCU=+b=
} d{er|$E?
} B4`2.yRis
catch(IOException e){e.printStackTrace ();} Oo FgQEr@
catch(Exception e){e.printStackTrace ();} fuq( 2&^
"6?lQw e
>%-Hj6%
Utility.log(nFileLength); ,"~WkLI~\t
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'S =sj}X
return nFileLength; 1TKEm9j]u
} hHcJN
b6 $,Xh
T!MZ+Ph`F
//保存下载信息（文件指针位置） dZPW2yf
private void write_nPos() !n|#|.0m
{ $z*@2Non
try{ >BBl7
output = new DataOutputStream(new FileOutputStream(tmpFile)); M2}np
output.writeInt(nStartPos.length); Vwjk[ DOL
for(int i=0;i<nStartPos.length;i++) \I?w)CE@R
{ {}V$`L8
// output.writeLong(nPos); >xT^RYS
output.writeLong(fileSplitterFetch.nStartPos); DhZ:#mM{
output.writeLong(fileSplitterFetch.nEndPos); e"]"F{Q
} &=YSM.G
output.close(); yH*hL0mO
} ODm&&W#*
catch(IOException e){e.printStackTrace ();} G 0hYFc u
catch(Exception e){e.printStackTrace ();} +a|"{
} Z+ixRch@-s
v2d<o[[C
M)L/d_4ka
//读取保存的下载信息（文件指针位置） 5?Bc Y;
private void read_nPos() ! 0^;;'
{ fV 3r|Bp
try{ ^V[/(Lq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =4eUAeH {w
int nCount = input.readInt(); >QXzMN}o
nStartPos = new long[nCount]; _IWxYp
nEndPos = new long[nCount]; AIb>pL{
for(int i=0;i<nStartPos.length;i++) =-_)$GOI'
{ g6WPPpqus
nStartPos = input.readLong(); X2qv^G,
nEndPos = input.readLong(); WE0}$P:
} ?]^zD k@~
input.close(); WZq,()h
} WJfES2N
catch(IOException e){e.printStackTrace ();} 2UiR~P]%
catch(Exception e){e.printStackTrace ();} cph~4wCS[U
} v,{h:
KF_?'X0=
f-4.WW2FN
private void processErrorCode(int nErrorCode) +td<{4oq8
{ 9e!vA6Fx
System.err.println("Error Code : " + nErrorCode); -IadHX}]t
} n@hl2M6.x9
:}Ok$^5s
OOokhZd`
//停止文件下载 /Y,r@D
public void siteStop() r$ =qQ7^#
{ zN%97q_
bStop = true; @D~B{Hg
for(int i=0;i<nStartPos.length;i++) ,9d9_c.T
fileSplitterFetch.splitterStop(); &f-hG3/M
ND5$bq Nu?
\@K~L4>
} gw^'{b
} V>Fesm"aq
//负责部分文件的抓取 +TH3&H5I_A
**FileSplitterFetch.java mk%b9Ko<F
*/ f8=]oa]
package NetFox; 6W&_2a7*
?1peF47Z
zPR8f-Uvw
import java.io.*; %m eLW&
import java.net.*; ,X68xk.'
eCWPhB6l
dQD$K|aUp
public class FileSplitterFetch extends Thread { IxOc':/jY
)1lu=gc
]!Oue_-;
String sURL; //File URL )o{aeV
long nStartPos; //File Snippet Start Position m2xBS!fm
long nEndPos; //File Snippet End Position io.]'">
int nThreadID; //Thread's ID px=]bALU
boolean bDownOver = false; //Downing is over 2/B)O)#ls
boolean bStop = false; //Stop identical 1oty*c
FileAccessI fileAccessI = null; //File Access interface xzm@ v(
e\F}q)_
G>w+#{(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F}36IM9/:
{ o5!f#Y
this.sURL = sURL; ~jN'J+_$
this.nStartPos = nStart; eh(<m8I
this.nEndPos = nEnd; sZg6@s=
nThreadID = id; A_R!uRD8-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ys8Q.oBv_`
} E7nFb:zlV
_w!a`w*3
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public void run() l+'F_a
{ \S4SI
while(nStartPos < nEndPos && !bStop) BMFF=
{ dU_;2#3m
S_b/DO
q/PNJ#<
try{ QA?oJ_}y
URL url = new URL(sURL); fDh]tua
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eKG2*CV
httpConnection.setRequestProperty("User-Agent","NetFox"); Zb_apjg[4
String sProperty = "bytes="+nStartPos+"-"; =:=/Gz1
httpConnection.setRequestProperty("RANGE",sProperty); =-#G8L%Q
Utility.log(sProperty); QR0(,e$Dl
p?# pT}1
nlc.u}#
InputStream input = httpConnection.getInputStream(); -tLO.JK<
//logResponseHead(httpConnection); c5% 6Y2W0
C&<~f#lB
pHC/(6?
byte[] b = new byte[1024]; 7K;!iX<d
int nRead; @?kJ).
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #_JYh?
{ Q@S-f:!
nStartPos += fileAccessI.write(b,0,nRead); e,0-)?5R
//if(nThreadID == 1) 3n]79+w@z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [XR$F@o
} :TalW~r|
np9dM
MYdO jcN
Utility.log("Thread " + nThreadID + " is over!"); 56}X/u
bDownOver = true; h8{(KRa6
//nPos = fileAccessI.write (b,0,nRead); B&0;4
} 2C=Q8ayvX
catch(Exception e){e.printStackTrace ();} 4aUiXyr*2
} %*}Y6tl'|
} "ju'UOcS/
iE].&>w
F@YKFk+a
//打印回应的头信息 646JDX[o
public void logResponseHead(HttpURLConnection con) g)"gw+ZFc
{ sG7u}r
for(int i=1;;i++) 12UD19!
{ m Y,|J\w@
String header=con.getHeaderFieldKey(i); K.~q+IYP[
if(header!=null) 3Q^fVn$tk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E_T2z4lw
Utility.log(header+" : "+con.getHeaderField(header)); ==N{1gO]
else HD>q(cK_|8
break; bulS&dAX
} xc@Ss[
} =qy@Wvj$
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public void splitterStop() 4rg2y]
{ soRv1)el
bStop = true; yx38g ca
} zeb=8Dg :
tq1CwzRX
4T6 {Y
} IxZb$h[
V)ig)(CT
Yf@e=:
/* L{-LX=G^
**FileAccess.java baV>N[F&
*//文件访问(定位，写) q*7<)VwI
package NetFox; PNs~[
import java.io.*; =FP0\cQ.
4GdX/6C.
').}Nz
public class FileAccessI implements Serializable{ tBbOY}.VD
yw-8#y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r!1D*v5&:
RandomAccessFile oSavedFile; i%m"@7.kk
long nPos; Mj#-j/{x{5
W !w,f;
XRx+Dddt;
public FileAccessI() throws IOException T;TA7{B
{ @gC=$A#
this("",0); l e4?jQQ@L
} +ZMls [
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t_^X$pL
public FileAccessI(String sName,long nPos) throws IOException Fb22p6r
{ Hmt^h(*/2
oSavedFile = new RandomAccessFile(sName,"rw"); [epi#]m
this.nPos = nPos; afBE{
oSavedFile.seek(nPos); Ysq'2
} {9Y+.46S
?'86d_8
g[RI.&?
public synchronized int write(byte[] b,int nStart,int nLen) 4fk8*{Y
{ y;wx?1)
int n = -1; ULrr=5&8
try{ !* Ti}oIo&
oSavedFile.write(b,nStart,nLen); Q1d'~e
n = nLen; '.Ed`?<p
} -i0(2*<
catch(IOException e) Un`^jw#_
{ o8/;;*
e.printStackTrace (); 4;n6I)&.(
} #} ~qqJ G2
-}O1dEn.
L37Y+C//
return n; {vUN+We
} 3vhnwDcK
"k*PA\U
gVQjL+_W
} 61puqiGG^
::Ke^dp
{~!q`Dr3?q
/* @1.QEyXG
**SiteInfoBean.java ?0? R
*/ Q_* "SRz
package NetFox; S5~VD?O,
-p3Re9
,@1p$n
public class SiteInfoBean { A+6 n#
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(py]LBZ
private String sSiteURL; //Site's URL <N\v)Ug`
private String sFilePath; //Saved File's Path W;bu2ym&Q
private String sFileName; //Saved File's Name 3)-/`iy#
private int nSplitter; //Count of Splited Downloading File 'RRmIx2X
06$!R/K
ST\$=
public SiteInfoBean() u[nyW3MZ
{//nSplitter的缺省值为5 }cT_qqw(f%
//default value of nSplitter is 5 @-UL`+
this("","","",5); .>Ljnk
} ^Wxad?@
>:D j\"o
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WVVJ
{ f|O{#AC
sSiteURL= sURL; Y3Vlp/"rB"
sFilePath = sPath; $)3%U?AP
sFileName = sName; #fT*]NN
this.nSplitter = nSpiltter; XsnF~)YW
0-~\ W(
X]\ \,
} :_!8 WB
^G6RjJxqp8
vAyFmdJ^
public String getSSiteURL() CPNL 94x
{ >3z5ww
return sSiteURL; B}PIRk@a1
} 8\{^|y9-
X]P:CY
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public void setSSiteURL(String value) W 4F\}A
{ k0T?-iM
sSiteURL = value; 035rPT7-2-
} v|U(+O
ZDbc
Me 5_4H&Sg
public String getSFilePath() |SyMngIY
{ r*Yi1j/
return sFilePath; 3B1cb[2y
} ^^5&QSB:'
8Y5
**}h&k&%2
public void setSFilePath(String value) Mbjvh2z
{ ) $PDo 7#
sFilePath = value; FJasS8
} `w]s;G[
y@\V+
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public String getSFileName() 7)s^8+
{ "~D]E7Q3y
return sFileName; E9;|'Vy<E
} (\SA*.)
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public void setSFileName(String value) 9<KAXr#
{ 1Tu *79A
sFileName = value; .'Vww
} S#+h$UVh
*4V=z#
\hB5@e4i2
public int getNSplitter() hiQha5
{ V7/I>^X
return nSplitter; Q[nEsYP
} iezO9`
gG/!,Q.Qh
fMOU$0]$<
public void setNSplitter(int nCount) R~Ne|V2
{ k1QpKn*
nSplitter = nCount; fl\ly`_
} #-bA[eQV
} TA{\PKA)
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~Q\3pI. |
/* 8 XU1/i7N
**Utility.java 1Z9qjV%^
*/ >yULC|'F&~
package NetFox; 3`k;a1Z#O'
{~F4WjHJp
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public class Utility { aoXb22]{
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l,kUhZ@W
public Utility() 5O\*h;U 6
{ 3g >B"t
a[ex[TRKe
_'(,
} uuQ(&
o93`|yWl
//线程睡眠 cJrmm2.0kD
public static void sleep(int nSecond) -4cXRv]
{ hRCed4qA
try{ /Z$&pqs!
Thread.sleep(nSecond); >/8yGBD
} dxmE3*b`
catch(Exception e) !_"fP:T>
{ Y*UA,<-
e.printStackTrace (); Vv ?-"\Z>
} >k'c'7/
} `DC2gJKk%
l g-X:Z.
//日志 {DR`;ea])1
public static void log(String sMsg) ndkti5L,
{ Cvf[/C+
System.err.println(sMsg); B#M5}QT|2
} Rp5#clsy
|]c8jG\h
DK$s&zf
public static void log(int sMsg) $fzaPD4.
{ f\jLqZY
System.err.println(sMsg); e:5bzk!~
} xftBSdVE
} mVy|{Oh
}b-g*dn]5
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/* uH(f$A
**TestMethod.java s{$(*_
*/ D ^x-^6^
package NetFox; 8@tPm$
](s'L8(x
6*3.SGUY
public class TestMethod { PBp^|t]E>
q,+yqrt
eN^qG 42
public TestMethod() 43@{JK9G
{ ///xx/weblogic60b2_win.exe ;S>])5<
try{ (Kv#m 3~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m8o(J\]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |y2w9n0D
SiteFileFetch fileFetch = new SiteFileFetch(bean); D/Mi^5H)
fileFetch.start(); sPR1?:0:
} MP>dW nl
catch(Exception e){e.printStackTrace ();} `-p:vq`
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fe9LEM8j
} [Ki0b^
-&-Ma,M?
apu4DAy&8
public static void main(String[] args) o/+13C
{ SF>c\eTtx
new TestMethod(); c5u@pvSP
} cj1cZ-
} ekWePL;rR2
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