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)); 7A>glZ/x
} _+nlm5
for(int i=0;i<nEndPos.length-1;i++) y &%2
{ N:rnH:g+:
nEndPos = nStartPos[i+1]; 12yX`9h>
} 2aGK}sS6
nEndPos[nEndPos.length-1] = nFileLength; d#nKTqSg
} <k2]GI-}h
} nL* SNQ_
51x)fZQ
Edav}z
//启动子线程 !CuLXuM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Og<UW^VR
for(int i=0;i<nStartPos.length;i++) YS&Q4nv-
{ ^1+&)6s7V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \YsYOFc|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9@z"~H
nStartPos,nEndPos,i); .cm$*>LW:x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :S{+|4pH
fileSplitterFetch.start(); [y$sJF7;I
} TfqQh!Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NpYzN|W:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [ f`V_1d3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vh^,8pPy
nEndPos = " + nFileLength); VBI~U?0
// fileSplitterFetch[nPos.length-1].start(); b$'}IWNV
u:D,\`;)
J;7O`5J
//等待子线程结束 mGqT_
//int count = 0; fRd^@@,[
//是否结束while循环 v/WvT!6V`
boolean breakWhile = false; |0/~7l
~!W{C_*N
_8"%nV
while(!bStop) /0qLMlL$
{ B@2VI 1%
write_nPos(); >~k"C,6
Utility.sleep(500); YV>]c9!q
breakWhile = true; X Sw0t8
2N:|BO>
cp>1b8l6?
for(int i=0;i<nStartPos.length;i++) /__@a&9t
{ o Kfm=TbY
if(!fileSplitterFetch.bDownOver) [Dq!t1
{ Qtpw0t"
breakWhile = false; DZ Q=Sinry
break; Ljjuf=]
} BSB;0OM
} G\ht)7SGgf
if(breakWhile) &*N;yW""f
break; F"Y.'my8
Sq,x57-
Cl5l+I\1
//count++; &I$MV5)u
//if(count>4) ("B[P/
// siteStop(); 3@/\j^U
} h+7THMI
gK8{=A0c
zn'F9rWx>
System.err.println("文件下载结束！"); F"<TV&xf
} &{c.JDO
catch(Exception e){e.printStackTrace ();} A7qKY-4B
} .v{ok,&
o1kY|cnGH
mew,S)dq!
//获得文件长度 9c@."O`
public long getFileSize() +bw>9VmG
{ AsW!GdIN
int nFileLength = -1; hc;8Vsa
try{ RrGFGn{
URL url = new URL(siteInfoBean.getSSiteURL()); MIJ^n(-G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &6`h%;a/&
httpConnection.setRequestProperty("User-Agent","NetFox"); 58@YWvAk
EBX+fzjQo
=k\V~8XZ
int responseCode=httpConnection.getResponseCode(); fGtUr_D
if(responseCode>=400) j:;[Y`2
{ |aovZ/b4
processErrorCode(responseCode); :Ej#qYi
return -2; //-2 represent access is error )E.!jL:g
} rVE!mi]%
K*_5M
m["`Op4
String sHeader; V_T.#"C4=z
pp#xN/V#a
~<?+(V^D
for(int i=1;;i++) \qAg]-
{ n5~7x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N%k6*FBp~
//Utility.log(in.readLine()); .m]"lH*
sHeader=httpConnection.getHeaderFieldKey(i); Oist>A$Z
if(sHeader!=null) ,X05&'@Z
{ a$*)d($
if(sHeader.equals("Content-Length")) N:]71+
{ Wz~=JvRHh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]c.1&OB7o
break; 1yS[;
} KTm^0:V[Oy
} ]b"Oy}ARW
else bZE;}d
break; t0 1@h_WS
} NT6OGBl&
} 1gwnG&
catch(IOException e){e.printStackTrace ();} S~9K'\vO
catch(Exception e){e.printStackTrace ();} 3:Mq40]x
CHeU?NtFps
Stkyz:,(
Utility.log(nFileLength); Ca&5"aki
iz&$q]P8
avmuI^LLs
return nFileLength; 4'ym vR
} L"|~,SVF
jIMT&5k
-_bnGY%,
//保存下载信息（文件指针位置） *f[nge&.
private void write_nPos() )]/gu\90
{ kPm{tc
try{ ETw7/S${
output = new DataOutputStream(new FileOutputStream(tmpFile)); D`?=]Ysz(
output.writeInt(nStartPos.length); J3F-Yl|
for(int i=0;i<nStartPos.length;i++) LyaFWx
{ aL9yNj}2
// output.writeLong(nPos); /A8ua=Kn
output.writeLong(fileSplitterFetch.nStartPos); 7hs1S|
output.writeLong(fileSplitterFetch.nEndPos); J|9kWjOf+i
} Uq:WW1=kh
output.close(); -bN;nSgb
} OT*C7=
catch(IOException e){e.printStackTrace ();} Z r}5)ZR.
catch(Exception e){e.printStackTrace ();} _.9):i2<SF
} x}Y
|,3>A@
TSGJ2u5ie%
//读取保存的下载信息（文件指针位置） g[Z$\A?ZbZ
private void read_nPos() #Sxk[[KwH*
{ cjf 8N:4N0
try{ i'w8Li
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 66P'87G
int nCount = input.readInt(); #y<KO`Es
nStartPos = new long[nCount]; iYqZBLf{S
nEndPos = new long[nCount]; cBZKt
for(int i=0;i<nStartPos.length;i++) 4GA9oLl
{ x)Y?kVw21"
nStartPos = input.readLong(); iP7 Cku}l
nEndPos = input.readLong(); toq/G,N Q
} @H{QHi
input.close(); #DBg8
} [Eeanl&x>
catch(IOException e){e.printStackTrace ();} rd*`8B
catch(Exception e){e.printStackTrace ();} 8T7ex(w
} )w?DB@Tx
%h}Qf&U_
,buSU~c_Q
private void processErrorCode(int nErrorCode) S(B$[)(
{ qXOWCYqs
System.err.println("Error Code : " + nErrorCode); WrA!'I
} uwQ~4
PQl^jS
lO (MF
//停止文件下载 [~3[Tu( C
public void siteStop() b`%3>
{ !cLdoX
bStop = true; eP d
for(int i=0;i<nStartPos.length;i++) ;Av=/hU
fileSplitterFetch.splitterStop(); W'|NYw_B
:]Nn(},
:%6OFO$z
} kPhdfF*Q
} jL }bGD
//负责部分文件的抓取 /5Od:n
**FileSplitterFetch.java DjyqQyq~
*/ 7L%JCH#F
package NetFox; Nl4,c[$C
y:Wq;xEiDo
~[_u@8l!mN
import java.io.*; PykVXZ7j;
import java.net.*; ;6 ?a8t@
@q98ac*{
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public class FileSplitterFetch extends Thread { IhIz 7.|
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Y X`BX$
String sURL; //File URL ^(j}'p,
long nStartPos; //File Snippet Start Position 1^f7
long nEndPos; //File Snippet End Position b< dwf[
int nThreadID; //Thread's ID ',WnT:
boolean bDownOver = false; //Downing is over "QKCZ8_C
boolean bStop = false; //Stop identical YiO3.+H
FileAccessI fileAccessI = null; //File Access interface i/vo
3WVH8Sb
Fy; sVB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,Y:ET1:
{ fY4I(~Q
this.sURL = sURL; r}**^"mFy
this.nStartPos = nStart; Qe[ejj1o:
this.nEndPos = nEnd; &RJ*DAmL
nThreadID = id; B\73Vf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kB)u@`</mV
} h SeXxSb:
?*zDsQ
l&/V4V-
public void run() :F |ll?
{ xU1_L*tu '
while(nStartPos < nEndPos && !bStop) |)+s,LT5
{ tJM#/yT
%,1xOl4l
"t.Jv%0=
try{ !K8Kw W|X
URL url = new URL(sURL); 9{GEq@`7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |erG cKk
httpConnection.setRequestProperty("User-Agent","NetFox"); yTxrbE
String sProperty = "bytes="+nStartPos+"-"; Vktc
httpConnection.setRequestProperty("RANGE",sProperty); jIL+^{K<
Utility.log(sProperty); &KYPi'C9!z
(#c|San
5K:'VX
InputStream input = httpConnection.getInputStream(); .E:3I!dH7
//logResponseHead(httpConnection); vg-Ah6BC{
#n7F7X
zA>LrtyK(=
byte[] b = new byte[1024]; EED0U?
int nRead; :>|dE%/e$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y+aKk6(_W
{ 0"F|)
nStartPos += fileAccessI.write(b,0,nRead); nO+-o;DbC
//if(nThreadID == 1) 6MD9DqD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AoU Pq
} 2il`'X
4,P(w+
VnYcqeCm
Utility.log("Thread " + nThreadID + " is over!"); /szwVA
bDownOver = true; /fSsh;F
//nPos = fileAccessI.write (b,0,nRead); 8\X-]Gh\^
} 2Ij,OIcdBE
catch(Exception e){e.printStackTrace ();} {>3J96
} :cxA
} +n%d,Pz
@DNwzdP
Y#5v5
//打印回应的头信息 J2Mq1*Vpq
public void logResponseHead(HttpURLConnection con) {E;oirv&
{ T,oZaJ<
for(int i=1;;i++) uq2C|=M-x\
{ kz*6%Cg*~
String header=con.getHeaderFieldKey(i); f<{f/lU@
if(header!=null) 2oF1do;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Dr)jB*yK
Utility.log(header+" : "+con.getHeaderField(header)); .OpG2P
else .6LlkM6[g
break; _-T^YeQ/
} bzXeG;c<7
} oF~+L3&X
:4r{t?ytXw
dBkM~"
public void splitterStop() a&Z,~Vp
{ GJ{XlH
bStop = true; I&6M{,rnM
} r;9 V7C
{4$aA*
DDq?4
} %a?\y_a=b
n)j0h-
I 6'!b/
/* p/qu4[Mm
**FileAccess.java P6I<M}p
*//文件访问(定位，写) Yr*!T= z
package NetFox; S"t\LB*'Ls
import java.io.*; ~dC.,"
z1^3~U$}
tVe=c
public class FileAccessI implements Serializable{ I.'/!11>
D<`M<:nq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /9A6"Z
RandomAccessFile oSavedFile; b BiTAP
long nPos; r8tW)"?
4TTrHs
+c8t~2tuN
public FileAccessI() throws IOException P}^Y"zF2
{ XtQwLH+F
this("",0); "D'rsEh
} ~.4y* &
&lgzNC9g%
~Zn|(
public FileAccessI(String sName,long nPos) throws IOException AmZW=n2^
{ {;|pcx\L6~
oSavedFile = new RandomAccessFile(sName,"rw"); 3B='f"G
this.nPos = nPos; ))dw[Xa
oSavedFile.seek(nPos); 1G6 \}El95
} C+t0Zen
O')=]6CQ*
h;#046-7
public synchronized int write(byte[] b,int nStart,int nLen) 5UJ ?1"J
{ zBK"k]rz
int n = -1; }Q*J!OH
try{ LJ;&02w@
oSavedFile.write(b,nStart,nLen); ff7#LeB9
n = nLen; !Eg2#a?
} &8pGq./lr=
catch(IOException e) !C|Z+w9Y
{ 3 l}9'j
e.printStackTrace (); ~;z] _`_Va
} M~7Cb>%<
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&Z3%UOY
return n; 8f1M6GK?
} Bd 0oA )i
kBLFK3i
6"o=`Sq
} c&P/v#U_
Qv`: E
S?6-I,]h
/* s)fahc(@E
**SiteInfoBean.java Q@W!6]*\
*/ =)G]\W)m
package NetFox; 6.a5%:
d#XgO5eyO
<.Pt%Kg^BS
public class SiteInfoBean { $P#x>#+[A
IN@o9pUjV
h-|IZ}F7
private String sSiteURL; //Site's URL v%c/eAF
private String sFilePath; //Saved File's Path 7M _ mR Vh
private String sFileName; //Saved File's Name G'u[0>
private int nSplitter; //Count of Splited Downloading File mr/?w0(C
k6J&4?xZ
"dGN0i
public SiteInfoBean() UmvnVmnv
{//nSplitter的缺省值为5 J<0d"'
//default value of nSplitter is 5 )HC/J-
this("","","",5); ll1N`ke
} b !y
zc=G4F01
{]cr.y]\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0%< hj
{ G3`9'-2q@c
sSiteURL= sURL; .%)uCLZr$
sFilePath = sPath; x/CM)!U)
sFileName = sName; P 4t@BwU$
this.nSplitter = nSpiltter; |/H?\]7
=4'V}p
MUsF
} 9a=>gEF],@
f^*Yqa
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public String getSSiteURL() & !ds#-
{ iNfAn&
return sSiteURL; =+K?@;?
} ]{#=WTp]
*l4[`7|
-)^vO*b 0
public void setSSiteURL(String value) #R:&Irh
{ ?>U=bA
sSiteURL = value; +p63J
} 9Bw#VQ
}eW<P079
mv#hy
public String getSFilePath() $OdBuJA
{ 'tw ]jMD
return sFilePath; wggB^ }~
} 6pSTw\/6
49M1^nMvoo
[T,^l#S1
public void setSFilePath(String value) ?T_MP"
{ EpNN!s=Q
sFilePath = value; \/<VJB uV
} 7I'C'.6iM
~ z3J4s
>W8"Ar
public String getSFileName() 1P[x.t#
{ UO&$1rV
return sFileName; >V?0#f45@
} h'};spv
B~ i
`7w-_o %
public void setSFileName(String value) +a^gC
{ y]+5Y.Cw$
sFileName = value; k9OGnCW\
} "FA.T7G
7@>/O)>(AS
]b;m~|9
public int getNSplitter() xx>hJ!
{ C 'MR=/sd
return nSplitter; !hZ: \&V
} \Z3K ~
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eK l;T
public void setNSplitter(int nCount) -$o0P'Vx
{ 7`;f<QNo
nSplitter = nCount; iLZY6?_^
} Ms,MXJtH
} dt:$:,"
a{r"$>0
r9&m^,U
/* yD7}
**Utility.java kMurNA=
*/ O7 aLW
package NetFox; ur8+k4]\"
5Y^"&h[/
:K]7(y7>
public class Utility { h#O9TB
|xcI~ X7Q
El5} f4sl
public Utility() K2yNIq_
{ cbyzZ#WRb
p9?kJKN
^@AyC"K
} -)oUb=Lk{
[,Go*r
//线程睡眠 }' AY#g
public static void sleep(int nSecond) ; $80}TY '
{ EZ .3Z`
try{ )S%t)}
Thread.sleep(nSecond); iBAP,cR?`
} z``wqK
catch(Exception e) /m"/#; ^l
{ iO5g30l
e.printStackTrace (); aim\3y~
} 8]&:'
} T8z?_ *k
y0mNDze
//日志 RSym9t90t
public static void log(String sMsg) UTyV6~
{ hk4t #Km
System.err.println(sMsg); {owuYVm
} ( ~5M{Xh
r)'vn[A
|} b+$J
public static void log(int sMsg) \6&Ml]1
{ `9K5 ;]
System.err.println(sMsg); 9m$;C'}Z
} <Pt?N2]A|
} Z)W8Of_
)ciP6WzzbI
I61S0lz/
/* vlbZ5
**TestMethod.java E^F<"mL*
*/ 50N4J
package NetFox; ~SQxFAto
~h@@y5<4
0W*{ 1W
public class TestMethod { L/tn;0
P{n#^4
hvw9i7#
public TestMethod() >Dr(%z6CN
{ ///xx/weblogic60b2_win.exe KN|<yF
try{ }<A.zwB<i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EYq?NL='
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [UzD3VPg
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~#*C,4m
fileFetch.start(); *pJGp:{6V?
} ^)gyKl:E'
catch(Exception e){e.printStackTrace ();} R}Lk$#S#
4$&l`yWU+
1^WGJ"1
} `]eJF|"
M-"j8:en
f"5O'QHGQK
public static void main(String[] args) LN5LT'CE
{ DYr#?} 40
new TestMethod(); 4@?0wV
} Ocx"s\q(
} j1K3|E
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