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)); Q^Lk^PP7
} ~8htg8CZ`
for(int i=0;i<nEndPos.length-1;i++) sz?/4tY
{ wv6rjg:7
nEndPos = nStartPos[i+1]; ~AX@o-WU
} Z(gW(O9h.V
nEndPos[nEndPos.length-1] = nFileLength; 5Vj t!%?r
} ?F!='6D}b
} uy t'
>&`S$1 o
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//启动子线程 ar!`8"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r^jiK\*
for(int i=0;i<nStartPos.length;i++) <hvVh9
{ J8>8@m6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hM/:zC:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), BB)(#yoi
nStartPos,nEndPos,i); |+|q`SwJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AfV a[{E
fileSplitterFetch.start(); BPH-g\q
} <,Z6=M`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @h91: hb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); P_:~!+W,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ([+u U!
nEndPos = " + nFileLength); -wizUp
// fileSplitterFetch[nPos.length-1].start(); .8I\=+Zi
3EHn}#+U
e2@{Ab
//等待子线程结束 o;#9$j7QP!
//int count = 0; Te:4z@?
//是否结束while循环 !}[,ODJ4 d
boolean breakWhile = false; q!sazVaDp
bV~z}V&
&E(KOfk#
while(!bStop) xKZLXQ'e-
{ 7[)IP:I>
write_nPos(); ap7ZT7KW
Utility.sleep(500); "B^c
breakWhile = true; i- v PJg1
e=yQFzQT)
[ BpZ{Ql
for(int i=0;i<nStartPos.length;i++) ;#goC N.
{ t[yu3U
if(!fileSplitterFetch.bDownOver) YVpsf8R
{ @'Y^A
breakWhile = false; `wzb}"gLsM
break; 5R?[My
} |IL/F]I
} 9 K.B
if(breakWhile) YH 5jvvOI
break; hyPVt6Gkj
)fRZ}7k:
l4:5(1
//count++; zK5/0zMZ
//if(count>4) bJ$6[H-:
// siteStop(); 9MI~yIt`L
} a(qij&>
hS?pc<~`#
@`,~d{ziF
System.err.println("文件下载结束！"); m4=[e!
} |6ZH+6[
catch(Exception e){e.printStackTrace ();} Xqz\%&G
} AxsTB9/
)C@O7m*.4
d;<gwCc
//获得文件长度 rQuozbBb
public long getFileSize() Q^|ZoJS
{ !sJ*0
int nFileLength = -1; Rfk8trD B
try{ L355uaj
URL url = new URL(siteInfoBean.getSSiteURL()); x+=Ko
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $CXMeY{tOo
httpConnection.setRequestProperty("User-Agent","NetFox"); q$<M2
,bLHkBK
-_p+4tV
int responseCode=httpConnection.getResponseCode(); b%TS37`^[
if(responseCode>=400) whA
{ ;VLv2J*
processErrorCode(responseCode); 0# )I:5
return -2; //-2 represent access is error kzK4i!}
} Dm")\"5\?
us_o{
{#Lj,o
String sHeader; l$1z%|I
kwcH$w<I
BeNH"Y:E
for(int i=1;;i++) n' XvPV|
{ BkH- d z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YV6@SXy
//Utility.log(in.readLine()); |9Gng`)
sHeader=httpConnection.getHeaderFieldKey(i); z)Yk&;XC
if(sHeader!=null) w`N|e0G@
{ /9K,W)h_
if(sHeader.equals("Content-Length")) (Ov{gj^
{ H(JgqbFB*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tfSY(cXg'T
break; >I~$h,
} WeqE9@V
} uA'S8b%C
else &pL.hM^
break; WT-BHB1
} DaA9fJ7a
} \hm;p
catch(IOException e){e.printStackTrace ();} Rr9K1io$)
catch(Exception e){e.printStackTrace ();} 015 ;'V#we
?^8CD.|
X\z`S##kj
Utility.log(nFileLength); :jJ;&t^^
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\1[=t+/
return nFileLength; ;2NJkn9t
} MHuQGc"e+4
z]^u@]@NC
\),DW)
//保存下载信息（文件指针位置） MRI`h.
private void write_nPos() :RxWHh3O
{ }!&Vcf
try{ V!|:rwG2
output = new DataOutputStream(new FileOutputStream(tmpFile)); w$D&LA}(M
output.writeInt(nStartPos.length); y1oQ4|KSI
for(int i=0;i<nStartPos.length;i++) L.E6~Rv
{ y7x&/2
// output.writeLong(nPos); H*gX90{!2
output.writeLong(fileSplitterFetch.nStartPos); 6t,_Xqg*
output.writeLong(fileSplitterFetch.nEndPos); DE$HF*WY
} 5t,W'a_
output.close(); LU=<?"N6
} LNA5!E
catch(IOException e){e.printStackTrace ();} V5.=08L
catch(Exception e){e.printStackTrace ();} \8KAK3i'
} g }%$VUSA
bzl-|+!yB
M6j!_0j
//读取保存的下载信息（文件指针位置） "-WEUz
private void read_nPos() %u)niY-g
{ !"G|y4O
try{ cLZaQsS%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,>AA2@6zMT
int nCount = input.readInt(); N084k}io
nStartPos = new long[nCount]; "1-gMob
nEndPos = new long[nCount]; "8NhrUX
for(int i=0;i<nStartPos.length;i++) +(pFU\&U3H
{ Z [aKic
nStartPos = input.readLong(); 1 m>x5Dbk!
nEndPos = input.readLong(); 4U;Zs3
} |e]2 >NjQa
input.close(); ?}n\&|+
} ~8j4IO(
catch(IOException e){e.printStackTrace ();} k;fy8
catch(Exception e){e.printStackTrace ();} 8+?|4'\`
} L]syDn
mF6 U{=
HQ7
private void processErrorCode(int nErrorCode) KysJ3G.k\
{ k>'c4ay290
System.err.println("Error Code : " + nErrorCode); |)4aIa
} }(yX$ 3?`
Y\e8oIYu7
HgY>M`U
//停止文件下载 m|c5X)}-
public void siteStop() u> @Yoyc
{ ;;Y>7Kn!u
bStop = true; =8p *Ijs
for(int i=0;i<nStartPos.length;i++) 6]mFw{6qn1
fileSplitterFetch.splitterStop(); JtB]EvpL}
dB=aq34l
n{@^ne4m
} U.kTdNSp
} v=Y) A?
//负责部分文件的抓取 |_H{B+.
**FileSplitterFetch.java m0a<~
*/ #K4lnC2qz
package NetFox; oE;SZ"$x
q ?qpUPzD
6%^9`|3
import java.io.*; - / tzt
import java.net.*; Z'V"nhL
1%^d<%,]
^gu;
public class FileSplitterFetch extends Thread { h=7eOK]
1k:s~m?!
Ed^F_Gg#
String sURL; //File URL s7(I
long nStartPos; //File Snippet Start Position 8YLS/dN0 w
long nEndPos; //File Snippet End Position <:YD.zAh|
int nThreadID; //Thread's ID _]/&NSk
boolean bDownOver = false; //Downing is over @8$3Q,fF(
boolean bStop = false; //Stop identical ;/-X;!a>
FileAccessI fileAccessI = null; //File Access interface h{BO\^6x
MF}}o0P
flr&+=1?D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b- FJMY
{ Qk_Mx"
this.sURL = sURL; n#fc=L1U
this.nStartPos = nStart; U*R
this.nEndPos = nEnd; ZBf9Upg
nThreadID = id; !J%m7A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n~e#Y<IP\1
} d$O)k+j
}8\"oA6
-y1t;yU.L
public void run() C\d5t4s
{ \~{b;$N}
while(nStartPos < nEndPos && !bStop) h5>38Kd
{ ,TdL-a5
L3 VyW8Y
M,f|.p{,Y
try{ 9>1 $Jv3
URL url = new URL(sURL); Ts~)0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,2y" \_
httpConnection.setRequestProperty("User-Agent","NetFox"); 9tZ+?O5
String sProperty = "bytes="+nStartPos+"-"; Hc"FW5R
httpConnection.setRequestProperty("RANGE",sProperty); (9X>E+0E
Utility.log(sProperty); KDmzKOl
O:>9yZhV
%w0Vf$
InputStream input = httpConnection.getInputStream(); ^1 P@BRh
//logResponseHead(httpConnection); q&y9(ZvI
TzW1+DxM5
i(l'f#
byte[] b = new byte[1024]; hG3p"_L
int nRead; #ivN-WKCl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HxXCxI3
{ ncy?w e
nStartPos += fileAccessI.write(b,0,nRead); _?IP}}jA:
//if(nThreadID == 1) C6neZng
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g\n0v~T+
} 5{@Hpj/B
DwLl}{r'
NL-<K
Utility.log("Thread " + nThreadID + " is over!"); #P''+$5,
bDownOver = true; Oy `2ccQ#
//nPos = fileAccessI.write (b,0,nRead); yN Bb(!u
} 1D pRm(
catch(Exception e){e.printStackTrace ();} t;~H6
} k\J 6WT
} \1p_6U7
;J)8#|
~{O9dEI
//打印回应的头信息 D#~S<>u@
public void logResponseHead(HttpURLConnection con) I}@m6D|\
{ c_33.i"I}
for(int i=1;;i++) \~YyY'J
{ @fVCGV?'
String header=con.getHeaderFieldKey(i); LE"t'R
if(header!=null) o5 fXe}pl@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J:c]z9&!
Utility.log(header+" : "+con.getHeaderField(header)); \AT]$`8@_
else VgSk\:t
break; V=C@ocyZ
} #78P_{#!
} >^ E
m#(tBfH[
8w[nY.#T
public void splitterStop() (;11xu
{ .skR4f,h
bStop = true; :IZ(9=hs
} dX58nJ4u
Y\qiYra
RRNoX}
} B3P#p^
CulU?-[i
\I"UW1)B
/* UI*^$7z1 +
**FileAccess.java mh#dnxeR
*//文件访问(定位，写) Z(8'ki
package NetFox; G$5N8k[2
import java.io.*; f|*vWHSM
~)zoIM\
jDp]}d|f)
public class FileAccessI implements Serializable{ oH/4opV
[U]ouh)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $Yr'`(Cbc
RandomAccessFile oSavedFile; yW$ja|^E
long nPos; r~sx]=/
Y=oj0(Q*
2 NgEzY5
public FileAccessI() throws IOException Q}J'S5%
{ U#O6l-xe]
this("",0); _u`NIpXSP
} ?/_8zpW
ICD(#m
>@yHa'*9S
public FileAccessI(String sName,long nPos) throws IOException ~h~K"GbC?
{ H<M ggs-
oSavedFile = new RandomAccessFile(sName,"rw"); -$(,&qyk
this.nPos = nPos; K)Nbl^6x
oSavedFile.seek(nPos); i>9/vwe
} uA?_\z?
LF'M!C9|
web=AQ5I4
public synchronized int write(byte[] b,int nStart,int nLen) }57wE$9K
{ t5z6{`
int n = -1; T,72I
try{ Jlw oSe:S
oSavedFile.write(b,nStart,nLen); <}RU37,W
n = nLen; -R,[/7zj
} 2&E1)^
catch(IOException e) 1NO<K`
{ *v'&i) J
e.printStackTrace (); 0gBD
} Gd)@PWK
jfyV9)
f[n#Eu}
return n; IKM=Q. 7j
} ]@op
h:[PO6GdX
Ox"4 y
} v7O&9a;
G3P3
x.r~e)x=
/* J{=by]-rD,
**SiteInfoBean.java br"p D-}
*/ tvptawA.
package NetFox; ,cs`6Bd4
WlVC0&
Cw]Q)rX{
public class SiteInfoBean { fmH$1C<
I<*U^e
8=Di+r
private String sSiteURL; //Site's URL 2.Ym
private String sFilePath; //Saved File's Path xtKWh`[&
private String sFileName; //Saved File's Name 4J2NIFZ
private int nSplitter; //Count of Splited Downloading File $Q1:>i@I|g
CD(2A,u)/
HoGrvt<:.P
public SiteInfoBean() w,]cFT
{//nSplitter的缺省值为5 h\KQ{-Bl
//default value of nSplitter is 5 ;$(a+?
this("","","",5); i\G@kJNnF
} ^;GJ7y&,d
in-/
DY?`Y%"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eJ>(SkR:[
{ ghJ81
sSiteURL= sURL; >t u3m2
sFilePath = sPath; RX:\@c&
sFileName = sName; Ul OoMGg
this.nSplitter = nSpiltter; l%lkDh!$"
,T_HE3K
Z~$=V:EA?
} noa?p&Y1m
2}1(j
]*U\ gm%
public String getSSiteURL() It!%/Y5
{ {hK$6bD3^
return sSiteURL; `N}<lg(0#
} ?)-*&1cv
mgX0@#wFn
M[D`)7=b
public void setSSiteURL(String value) JAen=%2b
{ Fs<kMT
sSiteURL = value; Bm"jf]
} k&ujr:)5Y5
Skl1%`
<WtX> \]l(
public String getSFilePath() d~uK/R-KD
{ e`'O!
return sFilePath; 4VSIE"8e
} {w}PV5<
s#?Y^bgH
&G5+bUF,
public void setSFilePath(String value) w<&Nn`V
{ `,Q uO
sFilePath = value; 3>yb$ZU"-
} c'&3[aa
BgJ;\NV
/"tVOv#
public String getSFileName() ;2@MPx
{ v-Ggf0RF
return sFileName; -7TT6+H)
} 8},!t\j#]
/cexd_l|f
!0`44Gbq
public void setSFileName(String value) V/$qD
{ A5z`_b4f
sFileName = value; E {4/$}
} kM*f9x
;" '`P[
f8+($Ys
public int getNSplitter() DoX#+ 07u4
{ X3%7VFy9
return nSplitter; &9, 6<bToP
} -OZXl
Xgn^)+V:
O1Ey{2Q
public void setNSplitter(int nCount) $dFEC}1t
{ Tf Q(f?
nSplitter = nCount; FGG Fi(
} |L.QIr,jCC
} 66fvS}x
iE':ur<`
_OZrH(8
/* )i0\U
**Utility.java %L:e~*
*/ ?lnX."eAdB
package NetFox; AVGb;)x#
(ST/>")L
fBR,Oneo
public class Utility { (\e,,C%;
QB'-`GwL
8TD:~ee
public Utility() 5.0BaVwi
{ l6:k|hrm;
~#h@.yW^JN
aU<0<Dx
} -1Yt3M&
25XD fi75
//线程睡眠 vY7C!O/y_k
public static void sleep(int nSecond) J)oa:Q
{ id\0yRBt
try{ s+2\uMwf*
Thread.sleep(nSecond); Xnt`7L<L
} }at8b ^
catch(Exception e) S)C =Q~&
{ z|=l^u6uS
e.printStackTrace (); CtTG`)"|
} usZmf=p-r
} ;gcQ9L
# 5v 2`|)
//日志 { .B^
public static void log(String sMsg) :aV(i.LW
{ ,+3l9FuQ
System.err.println(sMsg); lj/?P9
} cR[)[9}
w")VcAq
@ eqVug
public static void log(int sMsg) @`G_6<.`
{ G5|xWeNgA
System.err.println(sMsg); ^2mmgN
} |eAl!k
} ,DqI> vx|
B'"C?d<7
SouPk/-B80
/* !lG5BOJM
**TestMethod.java ;JDn1(6
*/ ZMids"Xdf
package NetFox; ?;i O
\CM/KrCR
X@:pys 8@
public class TestMethod { M&Sjo' ( .
DNcf2_m
-^=gQ7f9
public TestMethod() |!euty ::
{ ///xx/weblogic60b2_win.exe ,Bk mf|
try{ mk~&>\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rY4{,4V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KFCrJ)
SiteFileFetch fileFetch = new SiteFileFetch(bean); p 2It/O
fileFetch.start(); ;Xk-hhR
} L#Uk=
catch(Exception e){e.printStackTrace ();} n"N!76
,-myR1}
OE]zC
} 1Y6<i8
@G+Hrd6
;:,hdFap
public static void main(String[] args) IeLG/ fB
{ mjO4GpG3
new TestMethod(); =o^oMn
} Qz2Yw `
} xQ\/6|
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