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)); R52q6y:<x
} )IZ$R*Y{
for(int i=0;i<nEndPos.length-1;i++) Ev0V\tl>0
{ s3kh (N
nEndPos = nStartPos[i+1]; mq'q@@:c
} W,Dr2$V
nEndPos[nEndPos.length-1] = nFileLength; _Zf1=&U#/
} E C7f
} WHAEB1c#Q
HEe0dqG
Pn7oQA\
//启动子线程 9zO;sg;3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9lTA/-
for(int i=0;i<nStartPos.length;i++) (nda!^f_s
{ :sT<<LtI-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L4kYF~G:4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i-E&Y*\^9H
nStartPos,nEndPos,i); qd{|"(9B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TqbKH08i/
fileSplitterFetch.start(); :^iR&`2~
} m@HU;J\I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6oUT+^z#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $$qhX]^~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;oR-\;]/.
nEndPos = " + nFileLength); ITbl%q
// fileSplitterFetch[nPos.length-1].start(); Ti' GSL
E) z g,7Y
c1n? @L
//等待子线程结束 RI*Q-n{
//int count = 0; 9,,v0tE
//是否结束while循环 7%w4?Nv3I
boolean breakWhile = false; wp*;F#:G
T,?^J-h^
i,RK0q?>
while(!bStop) >)S a#w;
{ SH}O?d\Q:
write_nPos(); 'm/b+9?.
Utility.sleep(500); f4w|
breakWhile = true; _bMs~%?~/
[9+M/O|Vs
N+}yw4lb
for(int i=0;i<nStartPos.length;i++) Uw)K[T
{ ;\iQZ~
if(!fileSplitterFetch.bDownOver) Q6vkqu5!=
{ 9Xm"kVqd/
breakWhile = false; {ZfTUt)-P
break; d0N7aacY
} d;CD~s
} p(x[zn+%Y
if(breakWhile) H<FDi{
break; j f^fj-
Y+G4:
H3b@;&`&
//count++; ,e,fOL
//if(count>4) }D|"$*
// siteStop(); +5T0]!
} 6SidH_&C
oHa6fi
!A<?nz Uv
System.err.println("文件下载结束！"); 'rCwPsI&4
} ex29rL3
catch(Exception e){e.printStackTrace ();} p6ZKyi
} 0c`wJktWK
u|w[b9^r
lFRgyEPH
//获得文件长度 `#l_`j=r$
public long getFileSize() %F{@DN`
{ zfxxPL'
int nFileLength = -1; G-;pMFP(?
try{ CP={|]>+S
URL url = new URL(siteInfoBean.getSSiteURL()); h7%<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jNB-FVaT
httpConnection.setRequestProperty("User-Agent","NetFox"); k-w._E <
`|]juc
7W 4[1
int responseCode=httpConnection.getResponseCode(); 6t@3 a?
if(responseCode>=400) &0N 3 p
{ *d)B4qG
processErrorCode(responseCode); XLOk+Fn
return -2; //-2 represent access is error CaK 0o*D
} Q+#, VuM
T@f$w/15
n!f@JHL
String sHeader; 7@06x+!
eP;lH~!.0
Z}XA(;ck
for(int i=1;;i++) *78TT\q<
{ t&-7AjS5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sdrE4-zd
//Utility.log(in.readLine()); E*k=8$Y
sHeader=httpConnection.getHeaderFieldKey(i); H!7/U_AH
if(sHeader!=null) J/ 4kS<c
{ Z(CzU{7c
if(sHeader.equals("Content-Length")) B(E+2;!QF
{ KZ&8aulP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X&(1DE
break; 7TlOF
} 2}hEBw68
} fF<~2MiKw
else _AK-AY
break; (i&:=Bfn)
} %~G)xK?W*
} $FS j^v]
catch(IOException e){e.printStackTrace ();} 4fQ<A <2/
catch(Exception e){e.printStackTrace ();} Z+FJ cvYx
9Yd<_B#
C+jlIT+
Utility.log(nFileLength); a$"3T
jIg]?4bW[
X`#vH8
return nFileLength; #sN]6
} ~xkcQ{
j%Usui<DL
J?LetyDNr]
//保存下载信息（文件指针位置） K#tT \
private void write_nPos() 1Sx2c
{ 7S}NV7
try{ 9J$N5
output = new DataOutputStream(new FileOutputStream(tmpFile)); /Rf:Z.L
output.writeInt(nStartPos.length); 2old})CLJ
for(int i=0;i<nStartPos.length;i++) &M&*3
{ xo a1='
// output.writeLong(nPos); -QN1=G4
output.writeLong(fileSplitterFetch.nStartPos); eD4X:^@
output.writeLong(fileSplitterFetch.nEndPos); WBK6Ug
} Kejp7okb
output.close(); B/0Xqyu
} ,K 8R%B
catch(IOException e){e.printStackTrace ();} -U.>K,M
catch(Exception e){e.printStackTrace ();} e];lDa#4-Y
} _Dr9 w&;<
GRM6H|.
@IhC:Yc
//读取保存的下载信息（文件指针位置） c#(Hh{0
private void read_nPos() -n FKP&P
{ Ra)wlIx
try{ FUzN}"\1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r2yJ{j&s
int nCount = input.readInt(); Swa0TiT(
nStartPos = new long[nCount]; :e/*5ix
nEndPos = new long[nCount]; GZH{"_$
for(int i=0;i<nStartPos.length;i++) KW-GVe%8f
{ 0v+-yEkw
nStartPos = input.readLong(); K*I!:1;3N
nEndPos = input.readLong(); u}3D'h
} ;`Nh@*_
input.close(); `>)[UG!:|
} cX7 O*5C
catch(IOException e){e.printStackTrace ();} e[ yN
catch(Exception e){e.printStackTrace ();} ja^_Lh9
} B6=?Qp/f
J-#V_TzJ?
3P@D!lV&K
private void processErrorCode(int nErrorCode) -M/j&<;LW
{ vjjVZ
System.err.println("Error Code : " + nErrorCode); n,U?]mr
} G/*;h,NbNr
?iZ2sRWR6
jr,N+K(@T
//停止文件下载 *Nm$b+
public void siteStop() +F-EgF+J
{ _%q~K (::
bStop = true; ^M{,{bG
for(int i=0;i<nStartPos.length;i++) G54J'*Z
fileSplitterFetch.splitterStop(); e2f+Fv 9
)/?H]o$NU
h5SJVa
} Y{D%v
} lD[37U!
//负责部分文件的抓取 <+k"3r{y"
**FileSplitterFetch.java /a'1W/^2
*/ 4qdoF_
package NetFox; U.KQjBi
u<Y#J,p`e
d2V X\
import java.io.*; O&1qL)
import java.net.*; f. "\~
|~r-VV(=
d{"-iw)t
public class FileSplitterFetch extends Thread { /M_$4O;*@
@^xtxtjzux
&W,jR|B
String sURL; //File URL Xx"<^FS[zC
long nStartPos; //File Snippet Start Position `PC9t)%.pV
long nEndPos; //File Snippet End Position *!%lBt{2
int nThreadID; //Thread's ID n:,mo}?X
boolean bDownOver = false; //Downing is over b~J)LXj]w
boolean bStop = false; //Stop identical DsejZ&
FileAccessI fileAccessI = null; //File Access interface Ut;`6t
>> zd
q0iJy@?A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ttt'X<9
{ KNUK]i&L
this.sURL = sURL; 64<;6*
this.nStartPos = nStart; Ix5&B6L8
this.nEndPos = nEnd; Mf1(4F
nThreadID = id; D5TDg\E
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _y@].G
} E5w;75,
$KK~KEZ2
J;C:nE|V
public void run() 98>GHl'lM
{ `#N/]4(j
while(nStartPos < nEndPos && !bStop) H$KO[mW}
{ X2z<cJG|d@
n t}7|h|
WMSJU/-P
try{ AcC &Q:g
URL url = new URL(sURL); c.ow4~>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X\AH^I6S
httpConnection.setRequestProperty("User-Agent","NetFox"); qN $t_
String sProperty = "bytes="+nStartPos+"-"; T5(S2^)o
httpConnection.setRequestProperty("RANGE",sProperty); qqrjI.
Utility.log(sProperty); *l+#<5x
aD^$v
@^P^-B
InputStream input = httpConnection.getInputStream(); 54gr'qvr
//logResponseHead(httpConnection); JvpGxj
&{}Mds
.Pb-{!$Ni
byte[] b = new byte[1024]; /wV|;D^ )
int nRead; l":W@R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N3%X>*'
{ %rzPh<>e
nStartPos += fileAccessI.write(b,0,nRead); JVZ-nHf(9
//if(nThreadID == 1) (_T{Z>C/J
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lc*>sOm9
} %FO{:@CH
h>-P/
w;z7vN~/O
Utility.log("Thread " + nThreadID + " is over!"); !"rPSGK*
bDownOver = true; ;cor\R
//nPos = fileAccessI.write (b,0,nRead); ekM? '9ez
} dY*q[N/pO
catch(Exception e){e.printStackTrace ();} EBj^4=b[
} 4,9$udiGY
} uDf<D.+5Ze
j4.wd RK
dbI>\khI
//打印回应的头信息 }>A q<1%
public void logResponseHead(HttpURLConnection con) );5o13h2
{ nhV"V`|d
for(int i=1;;i++) AK:cDKBO
{ iOE. .xA:
String header=con.getHeaderFieldKey(i); {o=?@$6C
if(header!=null) -%nD'qy,.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q7R]!zk
Utility.log(header+" : "+con.getHeaderField(header)); Ve,g9I
else $3-vW{<
break; nxLuzf4U5
} 9d(\/ 7
} 2MkrVQQ9g
x#rgFY,TY
d2k-MZuT6
public void splitterStop() (O.%Xbx3
{ -yqsJGY
bStop = true; 6{Wo5O{!\
} |3H+b,M5
_z\/{
Bo 35L:r|
} $( hT{C,K
_fAgp_)
5]xuU.w'
/* 0I}e>]:I
**FileAccess.java FpoHm%+
*//文件访问(定位，写) Lvk}%,S8t
package NetFox; TP }a9-9?
import java.io.*; G\.~/<Mg+
Z;0~f<e%
}^"6:;,
public class FileAccessI implements Serializable{ i"{O~[
sNf& "C!;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L/3A g* ]
RandomAccessFile oSavedFile; \pmS*Dt
long nPos; x4_IUIgh
rhv~H"qzW
B2`S0 H
public FileAccessI() throws IOException #Z&/w.D2
{ !_W:%t)g
this("",0); 1.hWgWDP
} }nmlN
j3-YZKpg
w.qtSW6M+
public FileAccessI(String sName,long nPos) throws IOException "*g+qll!5d
{ !MbzFs~
oSavedFile = new RandomAccessFile(sName,"rw"); [W[{ 4 Xu
this.nPos = nPos; Psb !Z(
oSavedFile.seek(nPos); C.j+Zb1Z(
} J^!;$Hkd
l#)X/(?;
JWVV?~1
public synchronized int write(byte[] b,int nStart,int nLen) .i0K-B
{ ' jciX]g
int n = -1; }{0}$#zu
try{ R2bqhSlF
oSavedFile.write(b,nStart,nLen); >P6"-x,["
n = nLen; 7iB!Uuc
} U,GSWMI/K
catch(IOException e) Q*M#e
{ h>Kx
e.printStackTrace (); g[xoS\d
} !2!~_*sGe
5epI'D
!j~wAdHk
return n; #qRoTtMq7
} z8=THz2f
.1QGNW
"1o{mvCkR
} pwSgFc$z
uWS]l[Ga
X'A`"}=_
/* lg^'/8^f
**SiteInfoBean.java r[9m-#)>
*/ X4!93
package NetFox; "&(/bdah?&
H4M=&"ll}
V 6}5^W
public class SiteInfoBean { 6@]o,O
$q!A1Fgk0
(Tx_`rO4VY
private String sSiteURL; //Site's URL 0aT:Gy;
private String sFilePath; //Saved File's Path m:BzIcW<\
private String sFileName; //Saved File's Name W]4Z4&
private int nSplitter; //Count of Splited Downloading File zDFNx:h
:s)cTq|3
If'q8G3]-
public SiteInfoBean() }:$cK(|
{//nSplitter的缺省值为5 ?;~!C2Zs
//default value of nSplitter is 5 N2:Hdu:
this("","","",5); C T~6T&'
} (g6e5Sgi>
Q:kg
5:PS74/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?XKX&ws
{ O:BdZ5 b
sSiteURL= sURL; qI'pjTMDY
sFilePath = sPath; (Jp~=6&lKf
sFileName = sName; Y7GsL7I
this.nSplitter = nSpiltter; py6<QoGV
a)|y0w)vV
L: $ `8
} C-pR$WM:HN
\g0vzo"u
M)13'B.
public String getSSiteURL() !vX4_!%
{ ~EtGR # N
return sSiteURL; v^A+LZ*d
} QQ?t^ptv
z+Xr2B
fY]"_P
public void setSSiteURL(String value) k(H&Af+
{ AKk=XAGW
sSiteURL = value; eKLvBa-{@
} }6Pbjm*
AA\)BNM
<B@NSj
public String getSFilePath() @9^OHRZX
{ w4fKh
return sFilePath; ?NBae\6r
} !7t&d
bQD8#Ml1
[G 9Pb)
public void setSFilePath(String value) wx-\@{E
{ k26C=tlkv"
sFilePath = value; 0 u*a=f=
} 08\w!!a:
cb-IRGF
!mv5i%3
public String getSFileName() QN*|_H@h
{ '2X$. ^aW
return sFileName; ^%!{qAp}Z
} [%k8l~ 6
628iN%[-
NV5qF/<M
public void setSFileName(String value) #cQ5-R-1
{ Z/,R{Jgt"
sFileName = value; %P}H3;2
} B/X$ZQ0
Y" =8wNbr
G#[A'tbKk
public int getNSplitter() V u")%(ix
{ )\yK61aX
return nSplitter; ;gBR~W
} 2]kGDeSr
k"#gSCW$
4?Y7.:x
public void setNSplitter(int nCount) ZH~bY2^;
{ <T>s;b
nSplitter = nCount; MK3h~`is
} Y. J!]|
} ;PaU"z+Je~
NU=2*gM
rp\`uj*D
/* 1v&!%9
**Utility.java !4Aj#`)
*/ 7R:j^"I@
package NetFox; ezw*Lo!
LqYyIbsvf
Tdh(J",d
public class Utility { {|>'(iqH"w
fTXip)n!r
Muwlehuq
public Utility() Cu`
{ ![Qi+xyc
xHt7/8wF
4Q!A w
} m 3UK`~ji
M|c_P)7ym
//线程睡眠 uZ8-?
public static void sleep(int nSecond) ~QSX 1w"
{ e?XFtIj$
try{ k.C&6*l!5;
Thread.sleep(nSecond); }E ]l4N2
} PVg<Ovi^d
catch(Exception e) ' pgPQM<
{ ZBDF>u@
e.printStackTrace (); JPF6zzl)
} *rTg>)
} &|Wqzdo?#
7j)ky2r#
//日志 GXxI=,L8F
public static void log(String sMsg) ~~Bks{"BS
{ cFc(HADM`r
System.err.println(sMsg); (rFiHv5
} <O7!(
c2NB@T9'v
=/K)hI!u
public static void log(int sMsg) H.ZF~Yuw
{ T1qbb*
System.err.println(sMsg); XB7*S*"!
} 46]BRL2 G
} Iuz_u2"C
~*bfS}F8I
/[dMw *SRz
/* p _[,P7
**TestMethod.java FzEs1hpl
*/ 9287&+,0r
package NetFox; {@CQ (
-+{[.U<1jk
uGz)Vz&3
public class TestMethod { 4GP?t4][
|dQz(z&6{5
!-tw
public TestMethod() Zb2pZhkW
{ ///xx/weblogic60b2_win.exe #w.0Cc
try{ hu$eO'M_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RWv4/=}(G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cW>=/
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;@=3 @v
fileFetch.start(); ;[;WEA
} t@R[:n;+
catch(Exception e){e.printStackTrace ();} wxqX42v
mDK*LL5]W
1q(Qr h
} 3F]Dh^IR9
#&T O(bk
k Nc-@B
public static void main(String[] args) p/ xlR[
{ mDz44XO
new TestMethod(); b9rQQS
} &V1d"";SZ
} P!Fykg
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