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)); JG @bl
} 9`yG[OA
for(int i=0;i<nEndPos.length-1;i++) s.&ewf\
{ y Dg
nEndPos = nStartPos[i+1]; xq+$Q:f
} 7Gd)=Q{uur
nEndPos[nEndPos.length-1] = nFileLength; Z(Fsk4,
} ,TPNsz|Q
} 6*9hAnH
RL7OFfMe
F#>?i}
//启动子线程 6C@,&2<yK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L)H'g
for(int i=0;i<nStartPos.length;i++) ikf!7-,
{ 0j\?zt?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6<jh0=$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k0~mK7k
nStartPos,nEndPos,i); :c3}J<Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H'|b$rP0@
fileSplitterFetch.start(); a<9gD,]P
} G,I[zhX\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q/&H3N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CKwrE]h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +X6xCE
nEndPos = " + nFileLength); %>Z;/j|#r
// fileSplitterFetch[nPos.length-1].start(); -02cI}e
,{P*ZK3u
gjB36R
//等待子线程结束 fWiefv[&
//int count = 0; ZlD\)6 dZ
//是否结束while循环 t"Ok-!c|
boolean breakWhile = false; !dQG 5v
.O!JI"?
[mX/]31
while(!bStop) B@g 0QgA
{ >MD['=J[d
write_nPos(); %&m/e?@%I
Utility.sleep(500); .U|irDO
breakWhile = true; dU%Q=r8R
mOji\qia
HnU; N S3J
for(int i=0;i<nStartPos.length;i++) DZo7T!
{ tUouO0_l
if(!fileSplitterFetch.bDownOver) .y'iF>QQ\
{ iIWz\FM
breakWhile = false; % C~2k?
break; x_Zi^]
} ;Q"xXT`;:
} j9"uxw@
if(breakWhile) V|GH4DT=
break; HE GMwRJG
xVk|6vA7
I\djZG$s;N
//count++; .^6;_s>FN
//if(count>4) _GEt:=DAP#
// siteStop(); 1@Abs
} gB/4ro8
>i^8K U
So>P)d$8+
System.err.println("文件下载结束！"); x\taG.'zX
} p!qV!:
catch(Exception e){e.printStackTrace ();} l&3f<e
} #ra"(/)
Q72}V9I9
]7<}EG
//获得文件长度 { FVLH:{U^
public long getFileSize() y/U(v"'4U
{ h| q!Qsnj'
int nFileLength = -1; fik*-$V`
try{ Ik[aiz
URL url = new URL(siteInfoBean.getSSiteURL()); n^F:p*)Q%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _$s ;QI]x
httpConnection.setRequestProperty("User-Agent","NetFox"); wz1fx>Q
/ZC/yGdIS_
zTA+s 2
int responseCode=httpConnection.getResponseCode(); tQ!p<Q= $)
if(responseCode>=400) A4;EtW+F
{ #4hxbRN
processErrorCode(responseCode); W(jXOgs+_
return -2; //-2 represent access is error F3BWi[Xh
} ) 0p9I0=
\HR<^xY
qg521o$*
String sHeader; Rb!|2h)
5]C}044
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for(int i=1;;i++) jUny&Alj
{ &T7|f!y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =Xwr*FTr
//Utility.log(in.readLine()); DH7B4P
sHeader=httpConnection.getHeaderFieldKey(i); b*C\0D
if(sHeader!=null) _i@{:v
{ fP|rD[
if(sHeader.equals("Content-Length")) &.dC%
{ sK1YmB :~a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SePPI.n
break; ]IX6>p,
} Af*e:}}
} w8MQA!=l
else -TIrbYS`
break; $raxf80A
} &x~&]
} 8GRp1'\Hi
catch(IOException e){e.printStackTrace ();} 2t9JiH
catch(Exception e){e.printStackTrace ();} syuW>Z8s
2'R;z<_
?-'m#5i"
Utility.log(nFileLength); /-Saz29f^Q
FE}!I
>j5,Z]
return nFileLength; h8R3N?S3#
} R$[nYw
XwI~ 0
XctSw
//保存下载信息（文件指针位置） . X(^E
private void write_nPos() x3./
{ Cxn<#Kf\-<
try{ *t_"]v-w
output = new DataOutputStream(new FileOutputStream(tmpFile)); "EA6RFRD
output.writeInt(nStartPos.length); N?Wx-pK
for(int i=0;i<nStartPos.length;i++) `2}Frw+?
{ %[1\d)
// output.writeLong(nPos); U<T.o0s=
output.writeLong(fileSplitterFetch.nStartPos); j@yK#==k
output.writeLong(fileSplitterFetch.nEndPos); 1_AB;^
} [73 \jT
output.close(); M4%u~Z:4h+
} D'{NEk@
catch(IOException e){e.printStackTrace ();} 2(SU# /,
catch(Exception e){e.printStackTrace ();} +[LG>
} )@vhqVv?
[#+yL
[r[IWy(}
//读取保存的下载信息（文件指针位置） @D?KS;#
private void read_nPos() =H<I` J'
{ h8nJt>h
try{ dC&OjBQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]lT8Z-h@
int nCount = input.readInt(); {}sF?wZf
nStartPos = new long[nCount]; ]xx}\k
nEndPos = new long[nCount]; 3q$[r_
for(int i=0;i<nStartPos.length;i++) iy<|<*s2D
{ > whcZ.8
nStartPos = input.readLong(); fX ^hO+f
nEndPos = input.readLong(); 1Q5:Vo^B#
} (D.B'V#>
input.close(); Yk;-]qi7
} )bd)noZi
catch(IOException e){e.printStackTrace ();} aUy!(Y
catch(Exception e){e.printStackTrace ();} &:>3tFQSH
} _u[2R=h
Rm&^[mv
u<g0oEs)
private void processErrorCode(int nErrorCode) ~pZ<VH;h
{ S7B7'[ru
System.err.println("Error Code : " + nErrorCode); p#\JKx
} 2`|gnVw
s%&/Zt
pmWt7 }
//停止文件下载 8Q{"W"]O7
public void siteStop() y[D8rFw
{ v)f;dq^z-
bStop = true; 6YHQ/#'G~
for(int i=0;i<nStartPos.length;i++) }&*wJ]j`L
fileSplitterFetch.splitterStop(); '%H\k5^
\&6^c=2=
#JAy
} /e:kBjysJ
} @TQzF-%#7
//负责部分文件的抓取 H@'f=Y*D
**FileSplitterFetch.java (^G@-eh
*/ FxFRrRRH@
package NetFox; @^2?97i c
fi,h`mdT?
t=;P1d?E;
import java.io.*; t@;r~Sb
import java.net.*; N^TE ;BM
{f(RYj
joRrsxFU
public class FileSplitterFetch extends Thread { =pCO1<wR
W=S<DtG2
O a%ZlEUF
String sURL; //File URL (-[73v-w
long nStartPos; //File Snippet Start Position [0?W>A*h
long nEndPos; //File Snippet End Position Q1'4xWu
int nThreadID; //Thread's ID _C%:AFPP>
boolean bDownOver = false; //Downing is over l+UUv]:1
boolean bStop = false; //Stop identical Tb[1\
FileAccessI fileAccessI = null; //File Access interface c gOkm}h
h@{mcz
cuoZ:Wh
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a;h.I}*]
{ v,d bto0
this.sURL = sURL; X-<l+WP
this.nStartPos = nStart; P#l"`C /
this.nEndPos = nEnd; T^DJ/uhd
nThreadID = id; \0fk^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YHOo6syk
} ,<t)aZL,A;
%F}i2!\<L
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public void run() fc<~R
{ ' 4.T1i,
while(nStartPos < nEndPos && !bStop) ?0x=ascP
{ 60#eTo?}o
ZZ324UuATX
)>(ZX9diV
try{ 61W[
URL url = new URL(sURL); LEC=@) B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OsV'&@+G>
httpConnection.setRequestProperty("User-Agent","NetFox"); O^~Z-;FA
String sProperty = "bytes="+nStartPos+"-"; Ih<.2
httpConnection.setRequestProperty("RANGE",sProperty); isU4D
Utility.log(sProperty); /^sk y!
}0}=-g&
V [Wo9Y\
InputStream input = httpConnection.getInputStream(); e0ULr!p
//logResponseHead(httpConnection); o/hj~;(]
FEA t6
FWW*f _L
byte[] b = new byte[1024]; N}ZBtkR
int nRead; [=TD)o>W(p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?k^~qlye
{ b ;>?m
nStartPos += fileAccessI.write(b,0,nRead); ;;K ~
//if(nThreadID == 1) J,*+Ak ~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZkryoIQ%=
} )I"I[jDw
k_`h (R
vP%}XEF
Utility.log("Thread " + nThreadID + " is over!"); Ot{~mMDp
bDownOver = true; CrB4%W:{
//nPos = fileAccessI.write (b,0,nRead); ?&-$Zog
} 8RT<?I^5
catch(Exception e){e.printStackTrace ();} G_`Ae%'h
} l:~/%=
} b(\Mi_J
{dYz|O<
LKBh{X0%(
//打印回应的头信息 q1Ad"rm
public void logResponseHead(HttpURLConnection con) Gkm{b[
{ F#^/=AR'
for(int i=1;;i++) 3e9UDN2
{ ^% L;FGaA
String header=con.getHeaderFieldKey(i); $Lz!04
if(header!=null) _ glB<r$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3Ww 37V>h
Utility.log(header+" : "+con.getHeaderField(header)); nrR2U`
else K >Q6
break; *M.,Yoj
} QO:Z8{21So
} J:@yG1VIp
]X> I(p@
$o/i / wcj
public void splitterStop() ]cM8TT
{ BIEq(/-
bStop = true; _WZ{i,
} j`#H%2W\;
qP-_xpu]R
:!^NjO
} -qBdcbi|x)
% s@
<zm:J4&>T
/* CF:L#r
**FileAccess.java ;ik,6_/Y
*//文件访问(定位，写) 0oZZLi
package NetFox; 6s>io%,:
import java.io.*; -hq^';,
uAs!5h
iRx`Nx<@
public class FileAccessI implements Serializable{ hl0\$
6uTC2ka[&R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u}P:9u&h6X
RandomAccessFile oSavedFile; O{\%{XrW
long nPos; abv*X1
3h$E^"
>I-rsw2
public FileAccessI() throws IOException eeBW~_W
{ =oM#]M'G+(
this("",0); 2%pU'D:
} olr-oi`4C
)CHXfO w
T]/5aA4
public FileAccessI(String sName,long nPos) throws IOException MPKrr
{ @^DVA}*b)
oSavedFile = new RandomAccessFile(sName,"rw"); "?kDR1=7A
this.nPos = nPos; f96`n+>xi
oSavedFile.seek(nPos); vz|(KN[
} 7yXJ\(6R_
CI\yP@DQ4
Vf.*!`UH
public synchronized int write(byte[] b,int nStart,int nLen) ~]].i~EV(
{ ti$60Up
int n = -1; @!j6y(@
try{ +FAxqCkA
oSavedFile.write(b,nStart,nLen); KFRf5^%
n = nLen; *&\6x}.I4
} c##tP*(
catch(IOException e) +>%51#2.Q
{ ! 2knSS
e.printStackTrace (); @t@B(1T
} UbGnU_}
2b,edJVt?
oO`a{n-
return n; +IWf~|s
} zY7M]Az
'rS\9T
B2*7H
} RZKx!X4=q
$CJf 0[|
^*+M9e9Z
/* nP<u.{q L
**SiteInfoBean.java {\NBNg(Vo
*/ l'M/et{:
package NetFox; |(2#KMEWa
)siWc_Z4
<Rs$d0/
public class SiteInfoBean { AWPgrv/
/OB)\{-
k.2GIc:5
private String sSiteURL; //Site's URL tQYV4h\Qj
private String sFilePath; //Saved File's Path ,fTC}>s4
private String sFileName; //Saved File's Name Dgc6rv#
private int nSplitter; //Count of Splited Downloading File K"|~D0Qgo
Mw"[2PA
JiO8EIM
public SiteInfoBean() Y2'HP)tfIw
{//nSplitter的缺省值为5 LAM{ ,?~
//default value of nSplitter is 5 Iw`|,-|
this("","","",5); N6p0`
} .Y^3G7On
I Z*)
ki}Li*)7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DfU= i'R
{ gdoaXw;Sy
sSiteURL= sURL; lZe-A/E
sFilePath = sPath; -sdzA6dp
sFileName = sName; w1(5,~OB
this.nSplitter = nSpiltter; S 1^t;{"
t^>P,%$
v@ qDR|?^
} 'vu]b#l3
ut]UU*g^$
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public String getSSiteURL() ePl+ M
{ BB9eQ: xO
return sSiteURL; W/u(9
} ZREy I(_
kka{u[ruA
6/Yo0D>M$
public void setSSiteURL(String value) :?= 1aiS
{ i92Z`jiR
sSiteURL = value; _A& [rBm|
} n9 FA`e
uOKD#
#*lDKn[vO
public String getSFilePath() d2US~.;>l
{ '@WBq!p
return sFilePath; 8tf>G(I{
} ;{&4jcV*
L0H^S)g
fhRu-
public void setSFilePath(String value) $G}k'[4C
{ P s|[
sFilePath = value; -kP2Brm
} oa5L5Zr,A
@"98u$5
[; $:Lr
public String getSFileName() 5 ';[|f
{ Au/'|%2#(
return sFileName; bO6cv{>x
} !B{(EL=g
k\/es1jOEh
QkTU@T6>o
public void setSFileName(String value) +!`$(
{ CN-4FI)1D9
sFileName = value; X MF? y
} < 0S\P=\
'Cz]p~oF
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public int getNSplitter() tBwPB#:W
{ 0|0IIgy
return nSplitter; FOPmvlA\-<
} G%i&C)jZ
Aq(,
)liNjY@
public void setNSplitter(int nCount) h]|2b0
{ \Km+>G
nSplitter = nCount; L+lye Ir'
} U}=H1f,
} y|9 LtQ
)^)|b5,
f_hG2Sk
/* #0#6eT{-
**Utility.java lfwBUb
*/ eR3MU]zF
package NetFox; `@:k*d
T0\[": A
[E}pU8.t6
public class Utility { pf=CP%L
!+Sd%2o
Fy_~~nI0
public Utility() 5hAs/i9_
{ IUh)g1u41O
MSt@yKq
n!NA}Oa
} (1Jc-`
^c sOXP=Yp
//线程睡眠 eN<?rVZl
public static void sleep(int nSecond) '1\UFz
{ 5Ak>/QF9
try{ K*j1Fy:
Thread.sleep(nSecond); ve(@=MJ
} ).$kp2IN
catch(Exception e) lstnxi%x
{ ~~WX#Od*$
e.printStackTrace (); m W4tW
} Psjk 7\
} ]jP0Z#
twPD'X!r
//日志 `{S4_'
public static void log(String sMsg) ob(~4H-
{ 3HX-lg`0
System.err.println(sMsg); Vvl8P|x.<
} FzFP 0
[8`^_i=#
`%0k\,}V
public static void log(int sMsg) kmsgaB7?
{ )7N$lY<
System.err.println(sMsg); NUX2{8gs
} |\q@XCGei
} "eKM<S
N*>&XJ#
KWT[b?
/* a[V4EX1E
**TestMethod.java st(Y{Gs
*/ G/}nwj\
package NetFox; d7L|yeb"
bRc~e@
lO^YAOY
public class TestMethod { [~IFg~*,
K9euNa
g6<D 1r
public TestMethod() SV_b(wP9
{ ///xx/weblogic60b2_win.exe je~gk6}Y
try{ %;tBWyq}_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); e{IwFX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J k FZd
SiteFileFetch fileFetch = new SiteFileFetch(bean); YH$whJ`W0
fileFetch.start(); {DGnh1
} BYsQu.N
catch(Exception e){e.printStackTrace ();} i@spd5.
}q[IhjD%
*Mr'/qp,
} _,]@xFCOH
D,;6$Pvg^
{,CvWL
public static void main(String[] args) bmGtYv
{ {'eF;!!Dy
new TestMethod(); W&Gt^5
} S?LUSb
} Hqm1[G)
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