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)); I|K!hQ"m
} :oC;.u<*8
for(int i=0;i<nEndPos.length-1;i++) *8;<w~
{ <1m`
nEndPos = nStartPos[i+1]; o"L8n(\
} *n# =3D
nEndPos[nEndPos.length-1] = nFileLength; %6^nb'l'C
} Qb%; |li
} hNkv lk'Ui
Vm8dX?
"oFi+']*
//启动子线程 y;4g>ma0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3 Fy CD4#
for(int i=0;i<nStartPos.length;i++) HINk&)FC
{ ]q[(z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gW4fwE^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), l,(:~KH|
nStartPos,nEndPos,i); 4}cxSl]jf!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E4Ez)IaKyi
fileSplitterFetch.start(); |;t{L^
} t0v>J9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7r)]9_[(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !O}e)t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _h,_HW)G
nEndPos = " + nFileLength); 3fXrwmBT8
// fileSplitterFetch[nPos.length-1].start(); ].aFdy
0kls/^0,
$)PS#ND&
//等待子线程结束 n_ ?+QF
//int count = 0; ,O-_Pv
//是否结束while循环 Rbr:Q]zGN
boolean breakWhile = false; gi5X,:[
m^m=/'<+
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while(!bStop) n+Conp/
{ QJiH^KY6
write_nPos(); x5pu+-h
Utility.sleep(500); `'3 De(
breakWhile = true; c(FGW7L<
-r_\=<(
jOGiT|A
for(int i=0;i<nStartPos.length;i++) 1=sL[I7<
{ @|">j#0
if(!fileSplitterFetch.bDownOver) C"0 VOb
{ )D'#>!Y
breakWhile = false; vfx{:3fO
break; |wQ3+WN|
} sKR%YK "A
} ;V?(j3b[
if(breakWhile) 0.nkh6?
break; {%^4%Eco
$?gKIv>g
kRbJK
//count++; ;pOV; q3j
//if(count>4) n&|N=zh
// siteStop(); B^zg#x#8
} 1uG)U)y/Q
\pTC[Ry1
^4Xsdh5
System.err.println("文件下载结束！"); {YrA[9
} i!3*)-a\~`
catch(Exception e){e.printStackTrace ();} oAB:H\
} `nEqw/I
r)Zk-!1
./0wt+
//获得文件长度 AS~!YR
public long getFileSize() .HqJ)OH
{ <ME>#,
int nFileLength = -1; BzWkZAX
try{ ?2,D-3 {
URL url = new URL(siteInfoBean.getSSiteURL()); 0o6o<ggi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /dvronG
httpConnection.setRequestProperty("User-Agent","NetFox"); ,g*3u
=-GxJPL
~Jsu"kr
int responseCode=httpConnection.getResponseCode(); y\-iGKz{0
if(responseCode>=400) /Ix5`Q)
{ ~dLbhjden
processErrorCode(responseCode); '|5o(6u'
return -2; //-2 represent access is error @.}Y'`9L
} /%p ~
QOrMz`OA
$""kZ
String sHeader; /iQh'rp
J>;r(j
`r3 klL,W'
for(int i=1;;i++) bXXX-Xc
{ gYk5}E-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6o9&FU
//Utility.log(in.readLine()); R;A8y
sHeader=httpConnection.getHeaderFieldKey(i); \{~CO{II
if(sHeader!=null) dvZlkMm
{ ]F>#0Rdc
if(sHeader.equals("Content-Length")) eK*oV}U-k
{ K4]ZVMm/*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `D=`xSEYl
break; UhkL=+PD
} ?YV# K
} `T7TWv"M
else `l.bU3C
break; I2SH j6-
} o&z[d
} hDZyFRg
catch(IOException e){e.printStackTrace ();} v.>K )%`#
catch(Exception e){e.printStackTrace ();} lVd-{m)
; 2V$`k
!hS)W7!ik
Utility.log(nFileLength); OU#p^5K
94t`&jZ&|u
6d/v%-3
return nFileLength; +s;Vfc$b]H
} xWK/uE(
kz6fU\U
B3?rR-2mEE
//保存下载信息（文件指针位置） {^uiu^RAc
private void write_nPos() jAy2C&aP
{ AcXVfk z
try{ *vIP\NL?H
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2*#i/SE_
output.writeInt(nStartPos.length); :?FHqfN?_
for(int i=0;i<nStartPos.length;i++) W ;+()vC
{ /]-yZ0hX0O
// output.writeLong(nPos); :Mh\;e
output.writeLong(fileSplitterFetch.nStartPos); /cUu]#h
output.writeLong(fileSplitterFetch.nEndPos); _FcTY5."S
} UHU ,zgM
output.close(); ZUS5z+o
} xaoR\H
catch(IOException e){e.printStackTrace ();} (&r` l&0
catch(Exception e){e.printStackTrace ();} c|aX4=Z
} W(4$.uZ)
Zby3.=.e
pYr+n9)^
//读取保存的下载信息（文件指针位置） zks7wt]A
private void read_nPos() LYd:S
{ Y`4 LMK[]
try{ ) )FLM^dj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &ynAB)
int nCount = input.readInt(); y0&vsoT
nStartPos = new long[nCount]; l`A&LQ[
nEndPos = new long[nCount]; 4E2/?3D
for(int i=0;i<nStartPos.length;i++) IhZn
{ ;bg]H >$U7
nStartPos = input.readLong(); Sf.OBU1rs
nEndPos = input.readLong(); 3RvDX p
} f>4|>kS
input.close(); Kn=EDtg
} .j^BWr
catch(IOException e){e.printStackTrace ();} PUZcb+%]h
catch(Exception e){e.printStackTrace ();} .oT'(6#
} 6~2upy~e
CnZEBAU
BKb#\(95*
private void processErrorCode(int nErrorCode) [{GN#W|AGP
{ SDE$ymPx
System.err.println("Error Code : " + nErrorCode); GRkN0|ovfj
} f_xvXf:
9Oq(` 4
"p|.[d
//停止文件下载 UA2KY}pz5
public void siteStop() { gs$pBu
{ f8N*[by
bStop = true; xLi3|^q
for(int i=0;i<nStartPos.length;i++) p8)R#QWz9
fileSplitterFetch.splitterStop(); $\/^O94-l
JN`$Fq+
.`*]nN{
} K*b* ]hf{
} 3#dz6+
//负责部分文件的抓取 C#yRop_d]o
**FileSplitterFetch.java @H4]Gp ]
*/ fsw[R0B
package NetFox; b6Z3(!] ]
|#<z\u }
GI,TE
import java.io.*; WG\ _eRj
import java.net.*; jn(!6\n"
$cJ fdE
~"J1@<
public class FileSplitterFetch extends Thread { e`LkCy[_
vxC];nCC#
'bSWJ/;p)
String sURL; //File URL %,HUn`
long nStartPos; //File Snippet Start Position YVgH[-`,
long nEndPos; //File Snippet End Position 5XB]p|YU~s
int nThreadID; //Thread's ID L*,h=#x(
boolean bDownOver = false; //Downing is over H&p:
boolean bStop = false; //Stop identical /^k%sG@?
FileAccessI fileAccessI = null; //File Access interface V]+y*b.60
Y~{<Hs
E0fMFG^P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =SeQ- H#
{ !o?&{"#+
this.sURL = sURL; Xa#.GrH6
this.nStartPos = nStart; AH/o-$C&
this.nEndPos = nEnd; cb0rkmO
nThreadID = id; Ay 4P_>^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !m9hL>5vR
} /!?Tv8TPp
;|?_C8
6S3D#SY
public void run() AzZhIhWl">
{ :Rv+Bm
while(nStartPos < nEndPos && !bStop) )AR-b8..o
{ ^gp]tAf
)[ZXPD
T$R#d&t
try{ VV}"zc^
URL url = new URL(sURL); f+s)A(?3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #V]8FW
httpConnection.setRequestProperty("User-Agent","NetFox"); fjy\Q
String sProperty = "bytes="+nStartPos+"-"; ]u$tKC
httpConnection.setRequestProperty("RANGE",sProperty); W'"?5} (
Utility.log(sProperty); h4 9q(085V
eWex/ m
(}>)X]
InputStream input = httpConnection.getInputStream(); x4wTQ$*1
//logResponseHead(httpConnection); LAlX|b
>Ovz;
j nSZ@u
byte[] b = new byte[1024]; H'/V<%
int nRead; /j$pV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Al8Dw)uG{
{ $ ~%Y}Xt*
nStartPos += fileAccessI.write(b,0,nRead); F {L#
//if(nThreadID == 1) y }R2ZO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hFr+K1
} Ij.mLO]
IZLCwaW
K39I j_3
Utility.log("Thread " + nThreadID + " is over!"); |;)_-=L0P
bDownOver = true; 8N9,HNBT$
//nPos = fileAccessI.write (b,0,nRead); mk!8>XvM
} JBJ?|}5k4c
catch(Exception e){e.printStackTrace ();} u?MhK#Mr
} Hf_ pe
} C6a-
85[ 7lO)[
~Y*.cGA
//打印回应的头信息 Ank_;jo
public void logResponseHead(HttpURLConnection con) dz/fSA
{ Cu24xP`
for(int i=1;;i++) {fl[BX]kZ
{ LK*9`dzv=G
String header=con.getHeaderFieldKey(i); `fX\pOk~e
if(header!=null) y_q1Y70i2r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;R2A>f~
Utility.log(header+" : "+con.getHeaderField(header)); h>[ qXz
else er1XZ
break; -UzWLVB^
} L[*cbjt[
} L&:A59)1k
Vraz}JV
nFGX2|d
public void splitterStop() ^/%Y]d$
{ W|rAn2H
bStop = true; *dBmb
} w%)RX<h dI
PyHL`PZZ
V/"RCqY4
} ;Wk3>\nT-
6]<yR> '
H\<0{#F
/* C\BKdx5;
**FileAccess.java yY49JZ
*//文件访问(定位，写) h;r^9g
package NetFox; |P|2E~[r
import java.io.*; &Fuk+Cu{
Zj ` ;IYFG
3PRU
public class FileAccessI implements Serializable{ Y`-q[F?\y
]|w~{X!b4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L1Yj9i
RandomAccessFile oSavedFile; 'w72i/
long nPos; 1'TS!/ll];
tq'hiS(b
s!D2s2b9e
public FileAccessI() throws IOException fQ!W)>mi
{ u0oTqD?
this("",0); T>#~.4A0
} 4,X CbcC
G^SJhdO(Q
>rP[Xox'
public FileAccessI(String sName,long nPos) throws IOException iS.gN&\z^
{ =+DhLH}8
oSavedFile = new RandomAccessFile(sName,"rw"); P2s\f;Dwr
this.nPos = nPos; mA,{E-T
oSavedFile.seek(nPos); f8r7SFwUv
} BLqK5~
<^KW7M}w*c
@RuMo"js
public synchronized int write(byte[] b,int nStart,int nLen) AOcUr)
{ P()W\+",n
int n = -1; I D-I<Ev
try{ hDUU_.q)D
oSavedFile.write(b,nStart,nLen); &1yErGXC
n = nLen; E U RKzJk
} -p7 HQ/
catch(IOException e) 3&M0@/
{ oPbziB8
e.printStackTrace (); |)%H_TXTy
} 46\!W(O~y
'4~I%Z7L
M($GZ~ b%A
return n; v6uRzFw
} 0ZI}eZA j
zYdieE\-
,`a8@
} Em{;l:;(W
W}zq9|p
3?_%|;ga
/* jll|y0
**SiteInfoBean.java ;KmrBNF
*/ (0_zp`)
package NetFox; IIBS:&;+-
bi@'m?XwJ
k_?OEkgUh
public class SiteInfoBean { Nqd9)WQ
]uh/!\
{]m/15/$C
private String sSiteURL; //Site's URL BAi0w{
private String sFilePath; //Saved File's Path w6mYLK%
private String sFileName; //Saved File's Name @/$i -?E
private int nSplitter; //Count of Splited Downloading File !>Q\Y`a,*
^vxNS[C`;
? }`mQ<~
public SiteInfoBean() ==%5Ci7qMy
{//nSplitter的缺省值为5 e8(Qx3T?b
//default value of nSplitter is 5 8o $` '
this("","","",5); 6jm/y@|F!
} u%"5<ll
;Kg7}4`I
D97 vfC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >X"\+7bw
{ hPgYKa8u
sSiteURL= sURL; pSYEC,0B
sFilePath = sPath; SsfC m C
sFileName = sName; CMv8n@ry
this.nSplitter = nSpiltter; V;J3lV<
/"~UGn]R
Q:y'G9b
} "<)Jso|
o^owv(
m&(qr5>b
public String getSSiteURL() v|]"uPxH?
{ jt*B0'Sa
return sSiteURL; q3K}2g
} mC(YO y
]\}MSo3
T;PLUjp}
public void setSSiteURL(String value) -'*<;]P+.
{ 01RW|rN
sSiteURL = value; pY\=f0]
} *ywr_9
7;Q4k"h
g\IwV+iDf
public String getSFilePath() rp[3?-fk
{ QX=x^(M$m
return sFilePath; yO7#n0q
} EUV8H}d5
&=:3/;c
ZYt<O
public void setSFilePath(String value) gMPp'^g]_
{ YZtd IG
sFilePath = value; M&Ln'BC
} n:1Ijh 1
e VQ-?DK
tAY{+N]f
public String getSFileName() WlGT&m&2
{ d 792#Dc
return sFileName; C'Y2kb
} <Kl$ek8
zE/\2F$
uq54+zC
public void setSFileName(String value) ]0|A\bE\S
{ 1_Av_X
sFileName = value; B/!/2x
} Nqz6_!
0bIgOLP
n:k4t
public int getNSplitter() Unb3 Gv#O
{ rQU6*f
return nSplitter; H?xYS| n
} QH,(iX6RY
o?a3hD
"QiLu=Rq
public void setNSplitter(int nCount) [9NrPm3d
{ x#R6Ez7
nSplitter = nCount; ?0+g.,9
} e:C4f
} nf1 `)tXG
P$*Ngt
\ a(ce?C
/* B_b5&M@
**Utility.java (-&d0a9N
*/ uaU2D-ft"
package NetFox; >V]9<*c
,j.bdlI#
jcBZ#|B7;
public class Utility { n5IQKYrg
wQ@:0GJH
uxh>r2Xr=
public Utility() Eciu^
{ V@O)7ND
6h %rt]g
g0B%3v
} G|8>Q3D
QgQ$>
//线程睡眠 RU~ku{8?
public static void sleep(int nSecond) KNj~7aTp
{ 9tVV?Q@)
try{ /4+(eI7
Thread.sleep(nSecond); 0 ]L
} ^M;#x$Y?
catch(Exception e) #h4FLF_w
{ ]6Awd A
e.printStackTrace (); `r~3Pf).4
} 9 Qa_3+.B
} ZrZDyXL
eR6vO5to
//日志 W7!iYxO
public static void log(String sMsg) w1aoEo"S
{ ylQj2B,CB
System.err.println(sMsg); SO[ u4b_"h
} [K'gvLt1
k6RVP:V
P+OS
public static void log(int sMsg) PiCGZybCA
{ D3P/: 4
System.err.println(sMsg); X ,^([$
} Pt/]Z<VL
} lI.oyR'
DX+zK'34
C_8_sbZ/
/* mZPvG
**TestMethod.java j0a=v}j3
*/ a }*i [
package NetFox; rPGj+wL5-
/@\R
BzO,(bd!PI
public class TestMethod { RwOOe7mv
?2dI8bG
YhS_ ,3E
public TestMethod() ^m&P0
{ ///xx/weblogic60b2_win.exe u#Jr_ze
try{ 32%Fdz1S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *h3iAcM8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K5BL4N
SiteFileFetch fileFetch = new SiteFileFetch(bean); #d-zH:uq
fileFetch.start(); $uyx
} TB+k[UxB
catch(Exception e){e.printStackTrace ();} k,k>w#&
P R3Arfle
1# z@D(
} @|Yn~PwKs
ka8Y+Gs
b.@4yW
public static void main(String[] args) m_@XoS yxI
{ cBZEyy&
new TestMethod(); >$E;."a
} g<.Is V
} ci$J?a
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