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)); _F@p53WE
} %8CT -mQ
for(int i=0;i<nEndPos.length-1;i++) sLdUrD%
{ 5w)^~#'
nEndPos = nStartPos[i+1]; DhNo +"!z
} d[e:}1
nEndPos[nEndPos.length-1] = nFileLength; gH^$Y~Lx
} $H-D9+8 7
} |4.o$*0Y
Q\#{2!I
)]>G,.9C}
//启动子线程 eH%L?"J~:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uuYH6bw*d
for(int i=0;i<nStartPos.length;i++) ^[}0&_L w
{ yF5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &rztC]jF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (GEi<\16[
nStartPos,nEndPos,i); yC0f/O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `JWYPsWk
fileSplitterFetch.start(); o1X/<.0+
} }SMJD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?ey&Un"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nj^q@h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'CX.qxF1;p
nEndPos = " + nFileLength); m>+,^`0
// fileSplitterFetch[nPos.length-1].start(); )xvx6?Ah|
)yNw2+ ~5
LlA`QLe
//等待子线程结束 c > mu)('U
//int count = 0; mE^tzyh
//是否结束while循环 cxD}t'T
boolean breakWhile = false; \gp,Txueb
ra%R:xX
B}q
while(!bStop) ,/?%y\:J
{ MeI2i
write_nPos(); a\&(Ua
Utility.sleep(500); Xh0wWU*
breakWhile = true; qBBYckS.
&=z1$ih>2\
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for(int i=0;i<nStartPos.length;i++) ~w1{zxs
{ -.b Io
if(!fileSplitterFetch.bDownOver) <RoX|zJw
{ i_0,BVC
breakWhile = false; A&|Wvb=
break; HTDyuqs
} hINnb7o
} rKzv8d
if(breakWhile) ;WvYzd9
break; ti{H(;;@
I|F~HUzA"
]{AOh2Z.hv
//count++; MdVCD^B
//if(count>4) 'HQ7 |Je
// siteStop(); |D;"D
} "rjv5*z^&
8K@"B
"[Qb'9/Jc
System.err.println("文件下载结束！"); `R=a@DQ
} x2j/8]'o
catch(Exception e){e.printStackTrace ();} t<!+b@l5
} %A)-m 69
7>PF~=
hl6,#2$
//获得文件长度 Ad]<e?oN=
public long getFileSize() Gd30Be2gd
{ 8zQ_xE
int nFileLength = -1; 9UeVvH
try{ kyW6S+#-
URL url = new URL(siteInfoBean.getSSiteURL()); ,J~,ga~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >a&?AP #
httpConnection.setRequestProperty("User-Agent","NetFox"); vQ-ixh
gdoJ4b
=bs.2aN&^
int responseCode=httpConnection.getResponseCode(); #&^ZQs<
if(responseCode>=400) [{S;%Jj*X/
{ !X5o7b)
processErrorCode(responseCode); jIAW-hc]
return -2; //-2 represent access is error .9T.3yQ
} do:QH.q8)
94T}iY.
x @1px&^
String sHeader; +(;8@"u
Z|2Eb*
;Y Dv.I
for(int i=1;;i++) b%Wd<N2
{ 9 '2=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wqJ*%
//Utility.log(in.readLine()); !2GHJHxv]c
sHeader=httpConnection.getHeaderFieldKey(i); N=>- Q)
if(sHeader!=null) Y3-]+y%l
{ d32@M~vD
if(sHeader.equals("Content-Length")) Z:I*y7V-
{ _ymJ~MK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~_ *H)|
break; (N,nux(0k
} F|ETug n
} 0(wf{5
else $ I#7dJ"*
break; Hab!qWK`
} O x{Q.l
} 0r1g$mKb
catch(IOException e){e.printStackTrace ();} s>T`l
catch(Exception e){e.printStackTrace ();} Uf# PoQ!y
ft{W/ * +_
&kb\,mQ
Utility.log(nFileLength); #-,g&)`]
/^J2B8y
/E)9v$!
return nFileLength; i#k-)N _$
} 8GY.){d!l
]22C)<
A 6:Q<
//保存下载信息（文件指针位置） }xqXd%uz
private void write_nPos() sN-oEqS
{ PJCnud F
try{ T0r<O_ubOA
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3:UA<&=s
output.writeInt(nStartPos.length); |B eA==
for(int i=0;i<nStartPos.length;i++) }f0u5:;Zth
{ w}d}hI
// output.writeLong(nPos); =Ci13< KQ
output.writeLong(fileSplitterFetch.nStartPos); QeL{Wa-2F
output.writeLong(fileSplitterFetch.nEndPos); Lj iI+NJ
} @.k5MOn
output.close(); }S,-uggz
} g&bwtEZ
catch(IOException e){e.printStackTrace ();} 2\5cjdy
catch(Exception e){e.printStackTrace ();} $R";
} 3EmcYC
~Yl<S(/4
>{QdMn
//读取保存的下载信息（文件指针位置） wk@yTTnb
private void read_nPos() dQai4e>[
{ :Dayv6g
try{ qtzFg#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [.a;L">
int nCount = input.readInt(); 66 N)
nStartPos = new long[nCount]; AeaPK
nEndPos = new long[nCount]; {|XQO'Wg
for(int i=0;i<nStartPos.length;i++) ge$LIsE8
{ ".E5t@ }?m
nStartPos = input.readLong(); R4SxFp
nEndPos = input.readLong(); fe';b[q)#
} O~6Q;qP
input.close(); %9X{{_
} xorTL8
catch(IOException e){e.printStackTrace ();} -E]Sk&4Gj
catch(Exception e){e.printStackTrace ();} V!xwb:J
} ESIzGaM
5z~\5x
e/>:K' {
private void processErrorCode(int nErrorCode) Oqmg;\pm
{ # kEOKmO
System.err.println("Error Code : " + nErrorCode); 7@IFp~6<qK
} (Xo SG
b_=8!Q.:
thptm
//停止文件下载 b=1%pX_
public void siteStop() \?&Au
{ w;+ br
bStop = true; q@kOTkHv)
for(int i=0;i<nStartPos.length;i++) z]$>+MH_
fileSplitterFetch.splitterStop(); SX+4HJB
30_ckMG"g
` 8UWE {
} 4P%m>[
} )* TF"
//负责部分文件的抓取 Me/\z^pF
**FileSplitterFetch.java $KX[Zu%
*/ ,H39V+Y*
package NetFox; kaQ2A
}lP5GT2
<uD qYT$6
import java.io.*; 7Ms90oE/c
import java.net.*; 6Y7H|>g)
hH`Jb77L
nU/;2=f<
public class FileSplitterFetch extends Thread { kXwi{P3D$
=IHje;s
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String sURL; //File URL [bjN f2
long nStartPos; //File Snippet Start Position iYKU[UP?
long nEndPos; //File Snippet End Position :wipE]~4t
int nThreadID; //Thread's ID }fA;7GW+9
boolean bDownOver = false; //Downing is over #s2B%X
boolean bStop = false; //Stop identical QU/3X 1W
FileAccessI fileAccessI = null; //File Access interface O?ktWHUx
c!Dc8=nE0m
Y)M8zi>b
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f^9&WT
{ {Q~7M$
this.sURL = sURL; P`TIaP9%E
this.nStartPos = nStart; fg&eoI'f
this.nEndPos = nEnd; c+2%rh1
nThreadID = id; V=}1[^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hz\WZ^
} `#6x=24
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\[#t<dD
public void run() vPmnN^
{ q*8lnk
while(nStartPos < nEndPos && !bStop) ^$Krub{|
{ Z]vL%Gg*!
^%#grX#
|J3NR`-R
try{ X:=c5*0e
URL url = new URL(sURL); kX2d7yQZz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E4HU 'y~
httpConnection.setRequestProperty("User-Agent","NetFox"); uGCp#>+
String sProperty = "bytes="+nStartPos+"-"; p=gX!4,9<
httpConnection.setRequestProperty("RANGE",sProperty); <1@ (ioPH
Utility.log(sProperty); -BhTkoN)
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U7H9/<&o
InputStream input = httpConnection.getInputStream(); };S0 G!
//logResponseHead(httpConnection); K)[8 H~Lm
8&E}n(XE
V'StvU
byte[] b = new byte[1024]; nPA@h
int nRead; T~k)uQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }htPTOy5
{ $1@,Qor
nStartPos += fileAccessI.write(b,0,nRead); tu}>:mk
//if(nThreadID == 1) #jS[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :"'nK6>
} ctJ&URCi#
O4Dr ]Xc]
P}r)wAt
Utility.log("Thread " + nThreadID + " is over!"); 4~|<`vqN
bDownOver = true; 3f&|h^\nD
//nPos = fileAccessI.write (b,0,nRead); Vb)zZ^va+
} rK|*hcy
catch(Exception e){e.printStackTrace ();} '6S%9ahE
} 4JO@BV>t
} j[e,?!8;
edpW8eND
Kf.T\V4%
//打印回应的头信息 -cfx2;68
public void logResponseHead(HttpURLConnection con) V#^yX%
{ (vyz;Ob
for(int i=1;;i++) )#[|hb=o
{ `s/?b|,
String header=con.getHeaderFieldKey(i); ~F[L4y!sL
if(header!=null) !7 _\P7M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b^Cfhy^RTq
Utility.log(header+" : "+con.getHeaderField(header)); >D_F!_
else tZ8e`r*
break; 4v.d-^
} IXq(jhm8bL
} (bm;*2
&/WAZs$2n
]gP5f@`
public void splitterStop() QLr9dnA
{ e!X(yJI[O6
bStop = true; 3S"] u}
} CL9yEy"V
>K)2NLW\xA
@d&H]5
} nk@atK,38^
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S`=WF^
/* 5%i:4sMx *
**FileAccess.java )K0i@hM(n
*//文件访问(定位，写) p>kq+mP2bc
package NetFox; 4Z5#F]OA7
import java.io.*; Ix8$njp[
ht6244:
8Y{s;U0n
public class FileAccessI implements Serializable{ 1oY^]OD]W
QLo(i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `f`TS#V
RandomAccessFile oSavedFile; 1ThqqB
long nPos; ` \ZqgX4
xeA#u J
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public FileAccessI() throws IOException WUoOGbA `
{ ,YLF+^w-
this("",0); =r4!V>
} S~yR5cb
w{,4rk;Hr
7$uJ7`e
public FileAccessI(String sName,long nPos) throws IOException |a(fejO3
{ w*!wQ,o
oSavedFile = new RandomAccessFile(sName,"rw"); N4{nG,Mo]
this.nPos = nPos; )D@~|j:
oSavedFile.seek(nPos); Fo|xzLm9*|
} <+U|dX
^DAu5|--R
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public synchronized int write(byte[] b,int nStart,int nLen) WxUxc75
{ ,.mBJSE3
int n = -1; eN>0wd5{L
try{ %J7UP4
oSavedFile.write(b,nStart,nLen); 3S~(:#|
n = nLen; e XV@.
} lj[,|[X7`
catch(IOException e) R.RSQk7;
{ ZI13
e.printStackTrace (); P~ 0Jg# V
} Le#spvV3J|
j,-C{ K
"8<K'zeS8
return n; ZFn(x*L
} = !2NU
/n{1o\
ff2d@P,!
} TwahR:T
5J.0&Dda
~^US/"
/* @F5f"8!.\
**SiteInfoBean.java X_TiqV
*/ 4 J^Q]-Z
package NetFox; ?u$u?j|N
S\x=&Rz
.zj0Jy8N
public class SiteInfoBean { ql{_%x?
n=sXSxl
1y"3
private String sSiteURL; //Site's URL 2&LQg=O
private String sFilePath; //Saved File's Path u?H 2%hD
private String sFileName; //Saved File's Name 7[#xOZT
private int nSplitter; //Count of Splited Downloading File 't (O$
)P Jw+5
\Sy7"a
public SiteInfoBean() -*ELLY[
{//nSplitter的缺省值为5 iLX_T]1
//default value of nSplitter is 5 gwB\<rzG
this("","","",5); l?qqqB
} k5BXirB
PGn);Baq
]!"S+gT*C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]`o!1(GA
{ sfD5!Z9#1
sSiteURL= sURL; {3\R|tZh,`
sFilePath = sPath; D{7w!z
sFileName = sName; &%=D \YzG
this.nSplitter = nSpiltter; X]j)+DX>
.IrNa>J~
,J=P,](
} LEWhb!U
M4f;/`w
Gwec4D
public String getSSiteURL() S/A1RUt
{ :<S<f%
return sSiteURL; 1}m3;
} vsyWm.E
UXr5aZ7y
n.6T OF
public void setSSiteURL(String value) l$Gl'R>>*
{ pHE}ytcT
sSiteURL = value; mqtg[~dNc
} j6:7AH|!)2
f i~I@KJ>
KM,|} .@:
public String getSFilePath() dbdM"z4
{ o @Z#
return sFilePath; {=:#S+^ER
} </zXA$m
<O~WB
vRQOs0F;
public void setSFilePath(String value) a>mMvc"
{ U7$WiPTNL9
sFilePath = value; ;iYff N
} .giz=*q+
P1>AOH2yG
q1VH5'p@
public String getSFileName() ]2SF9p_
{ N#xG3zZl|N
return sFileName; 4\otq%Y
} Q+q,!w8
IND]j72
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public void setSFileName(String value) dR^"X3$
{ j+4H}XyE
sFileName = value; M" lg%j
} ;az5ZsvN D
yzsab ^]
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public int getNSplitter() |`d0^(X
{ zy'D!db`Z
return nSplitter; ,zTb<g
} eet Q}]
]bdFr/!'S+
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public void setNSplitter(int nCount) :nY2O
{ oFsM6+\/S
nSplitter = nCount; 0u B'g+MU`
} E ]9\R
} (@0O
24c ek
:aLT0q!K
/* ~V=<3X
**Utility.java ,"0)6=AE
*/ K4Dp:2/K%
package NetFox; ^D^JzEy'?C
=WZqQq{
`6Qdfmk=
public class Utility { 9Z"+?bv/
FyoEQ%.bI
-f1k0QwL
public Utility() m#/_x
{ mog[pu:!,
[%A4]QzWh
EpJ4`{4
} /Dtd#OAdr
zLw{ {|
//线程睡眠 :wqC8&V
public static void sleep(int nSecond) r,P1^uHx
{ G$zL)R8GE|
try{ _?voU
Thread.sleep(nSecond); 1k%k`[VC
} %6%<?jZ
catch(Exception e) C#;jYBtT7?
{ m(iR|Zx
e.printStackTrace (); _Us*+ 2(4L
} ^i)hm
} AdZ;j6#
=,!\~`^
//日志 -~" :f8
public static void log(String sMsg) C`jM0Q
{ `i +g{kE2M
System.err.println(sMsg); 5qUTMT['T
} n(nBRCG)o
ixm&aW6<
5v)(8|.M
public static void log(int sMsg) h4pTq[4*
{ q_W0/Ki8
System.err.println(sMsg); sAJ7R(p
} $2DuB
} )\;Z4x;]U
h0Z{,s}
fEE /-}d
/* 8.=\GV
**TestMethod.java 'D1A}X
*/ M~*u;vA/
package NetFox; l=N2lHU
|]Z:&[D]i
FOwDp0
public class TestMethod { 8n BL\{'B[
wv QMnE8\
o'~5pS(wq
public TestMethod() ;Yfv!\^|
{ ///xx/weblogic60b2_win.exe Uawpfgc}
try{ /N>e&e[35\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WnwhSr2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +`M!D }!
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8l?piig#
fileFetch.start(); +QM@VQ
} *rZ^^`4R
catch(Exception e){e.printStackTrace ();} iGDLZE+?
}ZSQ>8a
MC((M,3L
} R8L_J6Kpa
uV-'~8
.O*bILU
public static void main(String[] args) O<)y-nx;X
{ m+{K^kr[
new TestMethod(); _mS!XF~`P
} xCzebG["
} cr?7O;,
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