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)); iv*V#J>
} .}q]`<]ze
for(int i=0;i<nEndPos.length-1;i++) ;f:gX`"\
{ +Mk#9r
nEndPos = nStartPos[i+1]; }Z\wH*s`
} l<(cd,
nEndPos[nEndPos.length-1] = nFileLength; >!L&>OOx
} HTV ~?E
} H3, ut
iK#/w1`
`\bT'~P
//启动子线程 ldGojnS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W^es;5
for(int i=0;i<nStartPos.length;i++) VPt9QL(
{ `5q ;ssu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yEq#Dr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5Fmav5
nStartPos,nEndPos,i); 8TE>IPjm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {CtR+4KD
fileSplitterFetch.start(); ]IZ>2!6r
} ?s?$d&h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `9Yn0B.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (luKn&826
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 54{q.I@n
nEndPos = " + nFileLength); +`B'r '
// fileSplitterFetch[nPos.length-1].start(); $IVwA
"X04mQn15
|t))u`~
//等待子线程结束 *RWm47
//int count = 0; |S&5es-yW
//是否结束while循环 KB!5u9
boolean breakWhile = false; i0:>Nk
:]PM_V|
P`S@n/}
while(!bStop) +f>cxA
{ glE^t6)
write_nPos(); -Fxmsi
Utility.sleep(500); x&Cp> +i
breakWhile = true; ; Y"N6%
2#vv$YD
=wG+Ao
for(int i=0;i<nStartPos.length;i++) Zp&@h-%YoD
{ 9XLFHV("
if(!fileSplitterFetch.bDownOver) !lTda<;]
{ ('C7=u&F
breakWhile = false; eS'yGY0b
break; fKHE;A*>%
} ,lt8O.h-l
} t9^A(Vh"-
if(breakWhile) FY'ty@|_s
break; c)}2K0
#aar9
&H||&Z[pk
//count++; M6rc!K
//if(count>4) >Kivuc
// siteStop(); =8Ehrlq
} }tG3tz0%fX
fvEAIs
kL>d"w
System.err.println("文件下载结束！"); @F~LW6K
} x;LzG t:w
catch(Exception e){e.printStackTrace ();} JWv{=_2w
} J~#$J&iKh
R"AUSO|{
~+G#n"Pn
//获得文件长度 `.%JjsD<
public long getFileSize() !ABiy6d
{ rJJ[X4$
int nFileLength = -1; &QNY,Pj
try{ aG+j9Q_
URL url = new URL(siteInfoBean.getSSiteURL()); cXnKCzSxZq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -|S]oJy
httpConnection.setRequestProperty("User-Agent","NetFox"); HYK!}&
i3VW1~.8
S'LZk9E
int responseCode=httpConnection.getResponseCode(); *\uM.m0$
if(responseCode>=400) K_/zuTy
{ DgHaOAdU
processErrorCode(responseCode); 3;[DJ5
return -2; //-2 represent access is error b:J(b?
} MZ>6o5K|
p(F" /
/9pM>Cd*Z
String sHeader; IA&L]
@n&<B`/
tK(g-u0N`(
for(int i=1;;i++) S4^N^lQ]
{ c{+AJ8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }8-\A7T
//Utility.log(in.readLine()); ? "/ fPV-
sHeader=httpConnection.getHeaderFieldKey(i); Iu@y(wyg
if(sHeader!=null) -r7]S
{ SqA J-_~
if(sHeader.equals("Content-Length")) A{eLl
{ S8d8%R~1=h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5kypMHJm
break; "=. t 36#
} 20RXK1So
} X-LA}YH=tS
else 8.J(r(;>
break; ;%C'FV e]
} v``-F(i$
} )E#2J$TD
catch(IOException e){e.printStackTrace ();} oR1^/e
catch(Exception e){e.printStackTrace ();} 5yZTcS z
Z?P~z07
nl aM
Utility.log(nFileLength); lv&mp0V+
+=q)
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return nFileLength; WE6a'
} B/JO~;{
v1JS~uDz
7dG79H
//保存下载信息（文件指针位置） Ys+OB*8AE
private void write_nPos() H5CR'Rp
{ $?G"GQ!.
try{ g>rp@M
output = new DataOutputStream(new FileOutputStream(tmpFile)); m([(:.X/IX
output.writeInt(nStartPos.length); oX@ya3!Pz
for(int i=0;i<nStartPos.length;i++) )tHaB,
{ kum#^^4G|
// output.writeLong(nPos); ^N}Wnk7ks'
output.writeLong(fileSplitterFetch.nStartPos); &3F}6W6A
output.writeLong(fileSplitterFetch.nEndPos); OO dSKf8
} 7?8wyk|x
output.close(); {5r0v#;
} DZ7 gcC
catch(IOException e){e.printStackTrace ();} .d;Iht,[
catch(Exception e){e.printStackTrace ();} $ ,SF@BhO
} {GDmVWG0q
mR\`DltoV
:F,O
//读取保存的下载信息（文件指针位置） PNF?;*`-{7
private void read_nPos() SzwQOs*
{ W7"{r)7
try{ 7|\@zQ h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `\`>0hlu
int nCount = input.readInt(); vu!d)Fy
nStartPos = new long[nCount]; n79QJl/
nEndPos = new long[nCount]; p.I.iAk%G^
for(int i=0;i<nStartPos.length;i++) 7(M(7}EKA
{ eI.2`)>
nStartPos = input.readLong(); $Nrm!/)*'}
nEndPos = input.readLong(); HoV^Y6
} d)cOhZy
input.close(); EN{]Qb06A
} !Cgx.
catch(IOException e){e.printStackTrace ();} 4(}J.-B
catch(Exception e){e.printStackTrace ();} D(p\0V
} '7wd$rl
\!IMaB]
2sNK
private void processErrorCode(int nErrorCode) LMi:%i%\
{ >Rvx[`|O!m
System.err.println("Error Code : " + nErrorCode); JO=[YoTr
} Djk C
Uz cx6sw
2%*MW"Q
//停止文件下载 {oc igR0
public void siteStop() E$9Ys
{ HEL!GC>#
bStop = true; c_aZ{S
for(int i=0;i<nStartPos.length;i++) 5D M"0
fileSplitterFetch.splitterStop(); MuoF FvAA
g%F"l2M
~\x:<)
} &l$Q^g
} 1O].v&{
//负责部分文件的抓取 kGpa\c g1
**FileSplitterFetch.java (b?{xf'G
*/ +3s%E{
package NetFox; 43?^7_l-
_&K
08X_}97#WF
import java.io.*; j!7`]
import java.net.*; y4h=Lki@
EbeI{-'aF
[E#UGJ@
public class FileSplitterFetch extends Thread { &g2 Eptx#
G}5#l
x^Yl*iq
String sURL; //File URL %Qg+R26U
long nStartPos; //File Snippet Start Position hcVJBK
long nEndPos; //File Snippet End Position eh1Q7~
int nThreadID; //Thread's ID ^pn(=4
boolean bDownOver = false; //Downing is over 1qV@qz
boolean bStop = false; //Stop identical ^[%%r3"$C
FileAccessI fileAccessI = null; //File Access interface V8eB$in
ZmOfEg|h\
.B#l5pfvP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3@5=+z~CW
{ %m:m}ziLQ
this.sURL = sURL; G-9iowS/A
this.nStartPos = nStart; l5l>d62
this.nEndPos = nEnd; SIBoCs5
nThreadID = id; eEhr140
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qV5DW0.
} G=;k=oX(
`eu9dLzH
.NtbL./=|
public void run() .0R v(Y
{ s2j['g5
while(nStartPos < nEndPos && !bStop) {3N'D2N
{ L4uFNM]
eZ"1gYqy
Bgmn2-
try{ E}%hz*Q)(
URL url = new URL(sURL); R/"x}B1d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qfcYE=
httpConnection.setRequestProperty("User-Agent","NetFox"); P0`Mdk371
String sProperty = "bytes="+nStartPos+"-"; Y(.OF Q
httpConnection.setRequestProperty("RANGE",sProperty); AoA!q>
Utility.log(sProperty); WyP W*
099sN"kf
~=R SKyzt
InputStream input = httpConnection.getInputStream(); q80S[au
//logResponseHead(httpConnection); =]3tUD
?\8?%Qk
D&HV6#
byte[] b = new byte[1024]; FI"`DMb}
int nRead; s1?[7yC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E( us'9c
{ vkLC-Mzm<
nStartPos += fileAccessI.write(b,0,nRead); bQ|V!mrN}
//if(nThreadID == 1) 1s1=rZ!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v&Kqq!DE
} !mXxAo
=@F&o4)r
r-,e;o>9
Utility.log("Thread " + nThreadID + " is over!"); AIA6yeaU
bDownOver = true; 7)h[Zy,A
//nPos = fileAccessI.write (b,0,nRead); pLv$\MiZ
} ;-UmY}MU
catch(Exception e){e.printStackTrace ();} g/13~UM\
} I(=V}s2
} QRLt9L
2w)-\/j}
> xIJE2
//打印回应的头信息 ja=F7Usb
public void logResponseHead(HttpURLConnection con) YJ(*wByM
{ G%d (
for(int i=1;;i++) ioPUUUb)
{ yoAfc
String header=con.getHeaderFieldKey(i); |p$spQ
if(header!=null) %'0TXr$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q\\gpCgp
Utility.log(header+" : "+con.getHeaderField(header)); M:5b4$Qh<
else .jMq
break; }MUn/ [x
} gk`zA
} +**!@uY
'=P7""mN5
%,ngRYxT#
public void splitterStop() JmEj{K<3I
{ F:mq'<Q
bStop = true; 0Ia($.1mY
} q\H[am
,]b~t0|B
k%^lF?_0I
} tDAhyy73
3j3N!T9
Fv<`AU
/* vzmc}y G
**FileAccess.java x`6<m!d`
*//文件访问(定位，写) ]vuwkn+)
package NetFox; _ 84ut
import java.io.*; /rSH"$
Ks}Xgc\
A/`%/0e
public class FileAccessI implements Serializable{ %\i9p]=
n@G[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >ooZj9:'
RandomAccessFile oSavedFile; "n*~Mj Ny
long nPos; Z(!00^
o6//IOZ
"W(Q%1!Wi
public FileAccessI() throws IOException CW<N: F.9
{ wb~@7,D
this("",0); J:skJ.Wx
} I[n^{8gz
UT="2*3gz
S]E.KLR?[;
public FileAccessI(String sName,long nPos) throws IOException ur$l Z0
{ [|l?2j\
oSavedFile = new RandomAccessFile(sName,"rw"); r;m)nRu
this.nPos = nPos; t'ZWc\
oSavedFile.seek(nPos); )aX,%yK
} 6S~sVUL9`
V%Sy"IG
EAeqLtFqs
public synchronized int write(byte[] b,int nStart,int nLen) |<O9Sb_
{ t:fFU1x
int n = -1; Q?X>E3=U
try{ +T8B:
oSavedFile.write(b,nStart,nLen); uw2hMt (N
n = nLen; D.mHIsX6\
} }K3x
catch(IOException e) >a}f{\Q
{ @/k@WhFZ
e.printStackTrace (); 5ms""LD/
} @Pt="*g
GH[wv<
]7e =fM9V;
return n; hqRw^2F
} 6"}?.E$
}3?n~s\)6f
@lvyDu6e
} "Y\_TtY
#UbF9})q
7NJhRz`_
/* R+CM`4CD
**SiteInfoBean.java O|w J)
*/ nR`ov1RH
package NetFox; ;amXY@RmH
w}=5ElB
!o$!Frc
public class SiteInfoBean { aE2.L;Tk?
t]-5 ]oI
x*/S*!vx\
private String sSiteURL; //Site's URL oJfr +3I
private String sFilePath; //Saved File's Path F;]%V%F.X
private String sFileName; //Saved File's Name -a-(r'Qc(
private int nSplitter; //Count of Splited Downloading File [Jv@J\
=%/)m:f!^
YIjTL!bA"
public SiteInfoBean() GI&h`X5,e
{//nSplitter的缺省值为5 KVJ_E!i
//default value of nSplitter is 5 f& CBU
this("","","",5); #B\"'8#
} AA7C$;Z15~
pa#IJ
s;A@*Y;v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )6aAB|
{ r9dyA5oD
sSiteURL= sURL; f`Fi#EKT
sFilePath = sPath; zE_i*c"`
sFileName = sName; Sm5H_m!
this.nSplitter = nSpiltter; ' MxrQ;|S
,S!azN=
}+sT4'Ah>
} Er{>p|n=
1@-Ns
<%"b9T`'
public String getSSiteURL() hq #?kN
{ ?F3h)(}
return sSiteURL; G nG>7f[v
} qo|WXwP2
aca=yDs2
}B1!gz$YNO
public void setSSiteURL(String value) g pOC`=
{ 1aTB%F
sSiteURL = value; V=*wKuB
} RVQh2'w
=z /dcC$r
bR)(H%I
public String getSFilePath() aYSCw3C<
{ )<tI!I][j
return sFilePath; @qYp>|AF
} q0zr E5
^=-y%kp"
sc,vj'r
public void setSFilePath(String value) 2_Z ? #Y
{ +csi[c)3E
sFilePath = value; {Sj9%2'M)
} AnX%[W "
&eX!#nQ_.
Ob<{G"
public String getSFileName() e0,|Wm
{ "9Q40w\
return sFileName; OD!& .%
} WL"^>[Vq
SR|`!
W~7A+=&
public void setSFileName(String value) ~XmLX)vO/
{ $arK(
sFileName = value; 9j6QX~,
} 1^}[&ar
`M^= D&Bf
4J/}]Dr5
public int getNSplitter() abfW[J
{ 4p,EBn9(
return nSplitter; ~yW4)4k;b
} "ozr+:#\
;"~ fZ2$U
2Tp1n8FV
public void setNSplitter(int nCount) M:[ %[+6
{ I7n"&{s"*
nSplitter = nCount; (<xfCH F5
} EWkLXU6t
} @a0DT=>dT
Ni-xx9)=
9\BT0kx
/* [`"ZjkR_J
**Utility.java .ufTQ?Fe
*/ zv\kPfGDK
package NetFox; AW!?"xdZ
n%.7h3
@v)p<r^M">
public class Utility { :2rZcoNb.
8"8t-E#?
oldA#sA$
public Utility() Ki$MpA3j
{ PIoLywpRn
SBfT20z[
yDegcAn?
} Kzm+GW3o[
AicBSqUke
//线程睡眠 3yU.& k
public static void sleep(int nSecond) (mTE;s(
{ lvBx\e;7P
try{ koZ*+VP=
Thread.sleep(nSecond); jD<{t
} uXJ;A *
catch(Exception e) vZaZc}AyL
{ U4C 9<h&
e.printStackTrace (); Gi?/C&1T
} V)~.~2$
} QSdHm
v4`"1Ss,K
//日志 AQ,' 6F9
public static void log(String sMsg) '$ =>
{ Mh:L$f0A%O
System.err.println(sMsg); l3Q(TH~I
} #*K}IBz
8<pzb}xK
p6#g;$V$
public static void log(int sMsg) i1NY9br
{ D%OQ e#!
System.err.println(sMsg); r%yvOF\>
} ~=6xyc/c
} +eK"-u~K
aW)-?(6>
mD$A4Y-'p
/* >~[c|ffyo/
**TestMethod.java H8Bs<2
*/ }Qn&^[[miL
package NetFox; Dwr)0nk
F;4vPbH+
)U7t
public class TestMethod { a!7A_q8M
?(Dq?-.
VM GS[qrG
public TestMethod() -D
{ ///xx/weblogic60b2_win.exe !;Yg/'vD-
try{ cl=EA6P\X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [!HEQ8 2g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "GMBjT8
SiteFileFetch fileFetch = new SiteFileFetch(bean); P;=n9hgHI
fileFetch.start(); f332J
} SPX$U5&
catch(Exception e){e.printStackTrace ();} Z_};|B}
=9O^p@Q#W
WM7oM~&{6
} 4B =7:r
R_W+Ylob
*4Thd:7 `
public static void main(String[] args) GK)?YM
{ BP'36?=Zo
new TestMethod(); -3t7*
} \qdHX
} s C%&cRQD
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