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)); h0.Fstf]
} ;6b#I$-J-
for(int i=0;i<nEndPos.length-1;i++) @gi Y
{ R|+R4'
nEndPos = nStartPos[i+1]; &ApJ'uC
} #]eXI $HP
nEndPos[nEndPos.length-1] = nFileLength; EJWMr`zdn
} rY!uc!
} DAu|`pyC%
Xq>e]#gR
-;P<Q`{I
//启动子线程 DQlaSk4hF_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b7AuKY{L
for(int i=0;i<nStartPos.length;i++) HnP;1Gi
{ oLr"8R\d>t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dWqFP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4(aesZ8h
nStartPos,nEndPos,i); cZ!s/^o?f
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iQ9#gPk_9
fileSplitterFetch.start(); U[A*A^$c}
} <Z m ,q}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gv[7h'}<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l(]\[}.5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "j a0,%3
nEndPos = " + nFileLength); ZHC sv]l
// fileSplitterFetch[nPos.length-1].start(); [QZ~~(R
2/7=@>|
Gr6ma*)y~t
//等待子线程结束 [BQw$8+n_
//int count = 0; "{x~j\<
//是否结束while循环 K%pmE?%,8
boolean breakWhile = false; #dpt=
q5vs;,_ |
/2@%:b)
while(!bStop) >|Jw,,uf
{ 4|$D.`Wu
write_nPos(); D} .t
Utility.sleep(500); 3-mw-;.
breakWhile = true; ,K9UT#h
34oLl#q*
ZM#WdP
for(int i=0;i<nStartPos.length;i++) @^` <iTK&p
{ /M3D[aR<d
if(!fileSplitterFetch.bDownOver) z'qVEHc)
{ 7%E1F)%
breakWhile = false; *(vq-IE\$
break; -YuvEm#f
} h+74W0 $
} zDl, bLiJ
if(breakWhile) O h"^
break; Mb>6.l
CD&m4^X5D
*[SsvlFt
//count++; `5 6QX'?
//if(count>4) 6#KI? 6
// siteStop(); jO,<7FPs5
} P+b^;+\1s
{;4PP463
Qi[D&47XO
System.err.println("文件下载结束！"); b;t]k9:"L
} -Y[-t;
catch(Exception e){e.printStackTrace ();} t~M<j|]k
} y[|g!9Rp
=+"'=o
;yZ N "r
//获得文件长度 +E [bLz^
public long getFileSize() *(`.h\+
{ %f-<ol
int nFileLength = -1; MzG ryM-
try{ &!a2%%1#N
URL url = new URL(siteInfoBean.getSSiteURL()); lBn*G&(P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iTt=aQjd
httpConnection.setRequestProperty("User-Agent","NetFox"); Az-!LAu9 R
3EZwF
6J 5)4^bk
int responseCode=httpConnection.getResponseCode(); [;=ky<K0E
if(responseCode>=400) 'YR5i^:t
{ Dy@\!F
processErrorCode(responseCode); 9(l'xuX
return -2; //-2 represent access is error ,>UmKrYo
} *i{.@RX?
->hxHr`!%a
m6x. "jG
String sHeader; `az`?`i7
cA%U
vs@:L)GW\
for(int i=1;;i++) spx;QLo
{ 2SJh6U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %^l&fM*
//Utility.log(in.readLine()); u}1vn}F{
sHeader=httpConnection.getHeaderFieldKey(i); +r$.v|6
if(sHeader!=null) / 3k\kkv!
{ 0tqR wKL
if(sHeader.equals("Content-Length")) ee_\_"
{ 9-Qtj49
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x!~OK::o8
break; %~5Q^3$O
} GF!{SO4
} GnOo+hB
else W`'|&7~
break; V 3]p3
} )M N yOj
} #Q@6:bBzv
catch(IOException e){e.printStackTrace ();} XC1lo4|
catch(Exception e){e.printStackTrace ();} ;0!Wd
9,5II0N L
62x< rph
Utility.log(nFileLength); 8~)[d!'
vEe
ijqdZ+
return nFileLength; &{/>Sv!6#
} s~$4bN>LD
(YJAT
mF}k}0
//保存下载信息（文件指针位置） Zax]i,Bx
private void write_nPos() $JB:rozE
{ C9H11g7{
try{ <M OL{jan
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,;P`Mf'YC
output.writeInt(nStartPos.length); e-cb?.WU?
for(int i=0;i<nStartPos.length;i++) gwaC?tf[
{ &8AS=v
// output.writeLong(nPos); >v_5xd9
output.writeLong(fileSplitterFetch.nStartPos); thPH_DW>eb
output.writeLong(fileSplitterFetch.nEndPos); !;*2*WuO;
} D Ok^ON
output.close(); aaugu.9
} ]A]E)*
catch(IOException e){e.printStackTrace ();} 70 UgKE
catch(Exception e){e.printStackTrace ();} RpK,ixbtA+
} 7 3z Y^x
*@arn Eu
~}0hN]*G
//读取保存的下载信息（文件指针位置） .&x?`pER
private void read_nPos() -mHhB(Td'
{ [a)~Dui0@\
try{ /Tf*d>Yh;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ptcLJ]+)
int nCount = input.readInt(); :5K~/=6x
nStartPos = new long[nCount]; f76|
nEndPos = new long[nCount]; CotMV^
for(int i=0;i<nStartPos.length;i++) Z)O>h^0
{ A%*DQ1N
nStartPos = input.readLong(); R,w54},
nEndPos = input.readLong(); }Q=se[((
} lMzCDx!m
input.close(); N"x\YHp
} FJ%R3N\
catch(IOException e){e.printStackTrace ();} #oroY.o
catch(Exception e){e.printStackTrace ();} TnBGMI,g'
} 3zA=q[C
y]pN=<*h5
]6%%X+$7
private void processErrorCode(int nErrorCode) Q xF8=p
{ ~:}XVt0%8
System.err.println("Error Code : " + nErrorCode); qv*uM0G6i
} 4fu\3A&
~sHZh
ckjVa\
//停止文件下载 %M)oHX1p
public void siteStop() Cb%.C;q
{ BdoC6H
bStop = true; v*'iWHCl,
for(int i=0;i<nStartPos.length;i++) ioY\8i
fileSplitterFetch.splitterStop(); d!QD vO
9 QCpXy
Kpp*^
} H=o-ScA
} gjegzKU
//负责部分文件的抓取 8 1KG1i)
**FileSplitterFetch.java &iND&>?
*/ p-yOiG8b}
package NetFox; a,57`Ks+n<
$|cp;~ 1
&Rl3y\ r
import java.io.*; enbN0
import java.net.*; (LT\ IJSM
'q};L6
>uchF8)e|
public class FileSplitterFetch extends Thread { 3n84YX{
zsMw5C
Fy_<Ui
String sURL; //File URL *L4]\wf
long nStartPos; //File Snippet Start Position _czbUl
long nEndPos; //File Snippet End Position vBnKu
int nThreadID; //Thread's ID q:-]d0B+
boolean bDownOver = false; //Downing is over 1^60I#Vr@
boolean bStop = false; //Stop identical V:(w\'wm
FileAccessI fileAccessI = null; //File Access interface l\sS?
2 -p
ycl>git]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f.$aFOn
{ ^!o1l-Y^gr
this.sURL = sURL; !7kLFW
this.nStartPos = nStart; KXx@ {cv
this.nEndPos = nEnd; PQ&Q71
nThreadID = id; /_:T\`5uO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DUuC3^R
} {glqWFT
2iR:*}5
tJh3$K\
public void run() 5&-j{J0iV
{ T[4[/n>i
while(nStartPos < nEndPos && !bStop) Q/3tg
{ *_{l
5v!DYx
"BLv4s|y7L
try{ "%}Gy>;
URL url = new URL(sURL); N[a ljC-R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gdf1+mi
httpConnection.setRequestProperty("User-Agent","NetFox"); [DotS\p!z
String sProperty = "bytes="+nStartPos+"-"; u>t|X}JH
httpConnection.setRequestProperty("RANGE",sProperty); @`IXu$Wm(
Utility.log(sProperty); ;o_V!<$
43{_Y]
s0\f9D
InputStream input = httpConnection.getInputStream(); n{.*El>{
//logResponseHead(httpConnection); ;e~{TkD
Msv*}^>
o8};e
byte[] b = new byte[1024]; 1Es*=zg
int nRead; Y0Hq+7x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +#-kIaU
{ ^&`sWO@=
nStartPos += fileAccessI.write(b,0,nRead); *;OJ~zT
//if(nThreadID == 1) [V> :`?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C-a*EG
} aDN6MZM
2,8/Cb
*l>[`U+
Utility.log("Thread " + nThreadID + " is over!"); IDGQIg
bDownOver = true; |5}rX!wS4
//nPos = fileAccessI.write (b,0,nRead); vgh^fa!/
} j.=UI-&m
catch(Exception e){e.printStackTrace ();} KrdZEi vb
} ih+*T1#:(
} IFd )OZ5
Xq8uY/j
!fQJL
//打印回应的头信息 .6O52E
public void logResponseHead(HttpURLConnection con) H )BOSZD
{ ),nCq^Bp
for(int i=1;;i++) iA55yT+
{ )(:+q(m
String header=con.getHeaderFieldKey(i); 4|zdXS
if(header!=null) L;1$xI8tx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); u%6Irdx
Utility.log(header+" : "+con.getHeaderField(header)); Z/89&Uy`h
else lj "Z
break; >\|kJ?h
} Cec9#C
} 5+e>+$2
TIcd _>TW
zuC58B
public void splitterStop() z+3<$Z
{ 5cyddlaat
bStop = true; kq)+@p
} 1s{ISWm
u @{E{
pY+.SuM
} d\~p5_5.
L.C ^E7;Z_
zY7*[!c2
/* x4CtSGG85f
**FileAccess.java BA~a?"HS
*//文件访问(定位，写) 0K=Qf69Y
package NetFox; CCbkxHMf|!
import java.io.*; .dD9&n;#^
0Y2\n-`z
eV[`P&j_C
public class FileAccessI implements Serializable{ P'a0CE%
Wmzq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !1ML%}vvB,
RandomAccessFile oSavedFile; cZNi~
long nPos; pwJ'3NbS
ZWf-X
q*~gWn>T
public FileAccessI() throws IOException GY oZ$p"C
{ 5h_<R!jA
this("",0); !UBy%DN~k
} jP1$qhp
bjPka{PBj
6eOrs-ty
public FileAccessI(String sName,long nPos) throws IOException VK@$JwdL
{ gKmX^A5<
oSavedFile = new RandomAccessFile(sName,"rw"); T?W[Z_D
this.nPos = nPos; nqZA|-}
oSavedFile.seek(nPos); UppBnw
} xj0cgK|!
PV?]UUc'n<
m!rwG(
public synchronized int write(byte[] b,int nStart,int nLen) F0@Qgk]\
{ @@'nit
int n = -1; uWUR3n
try{ 3LKB;
oSavedFile.write(b,nStart,nLen); M,crz
n = nLen; ao)Ck3]
} *f79=x
catch(IOException e) K1:a]aU?Iu
{ Wm<z?.lS
e.printStackTrace (); ;KZrl`
} HbNYP/MN3
Qm $(
-u6}T!
return n; o:_^gJ+|
} }0$mn)*k
vT?Q^PTO
. 3GnZR,L
} }c} ( 5
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RXBb:f
/* W@l+ciZ_
**SiteInfoBean.java 3@&bxYXm
*/ o>2e!7
package NetFox; c\M#5+1j
6G'<[gL j
'g]hmE
public class SiteInfoBean { IQT cYl
wuKl-:S;Vs
;P3>>DZ
private String sSiteURL; //Site's URL 2-~a P
private String sFilePath; //Saved File's Path [_h%F,_ A
private String sFileName; //Saved File's Name gF3TwAr
private int nSplitter; //Count of Splited Downloading File "ml?7Xl,n
QjLji+L
p"KU7-BfvC
public SiteInfoBean() Mec{_jiH&D
{//nSplitter的缺省值为5 8 4z6zFv?Q
//default value of nSplitter is 5 2 #KoN8%
this("","","",5); -&imjy<
} F<5nGx cC
"9qp"%
):krJ+-/y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .8]Y-
{ 6_*!|g
sSiteURL= sURL; Kh)FyV
sFilePath = sPath; BBvZeG $Y
sFileName = sName; 6)ycmu;!$
this.nSplitter = nSpiltter; N0Gf0i>
Uan,H1a
Yj3P 7k$c
} Te;gVG*
:lK4 db
ymtd>P"
public String getSSiteURL() :7\9xH
{ h4Ia>^@
return sSiteURL; J^fm~P>.
} PPa^o8jd
+e'X;
^/*KNnAWp
public void setSSiteURL(String value) I_?He'=0oU
{ a\pi(9R
sSiteURL = value; pW{8R^vKm
} /&h+t^l_Qj
"x&3Z@q7
?vu_k 'io
public String getSFilePath() %,|ztH/ Q
{ t^.'>RwW|
return sFilePath; )Pli})
} vBNZ<L\|a
}~Q5Y3]#~
5[4Z=RP
public void setSFilePath(String value) _UkmYZ/
{ )r9b:c\
sFilePath = value; o 7G> y#Y
} f jI#-
cOkgoL" 4
H?uukmZl
public String getSFileName() 4\p-TPM
{ x l0DN{PG
return sFileName; H] k'?;
} jJ~Y]dQi
-4flV D
;xK_qBIP
public void setSFileName(String value) /)9W1U^B
{ Kd3QqVJBz1
sFileName = value; :Q_x/+-
} {B0h+. C
nJJs%@y
cXN _*%
public int getNSplitter() qX$u4I!,
{ :[sOKV i
return nSplitter; =XT)J6z^"
} wGJjA=C
knT.l"
m&IsDAn
public void setNSplitter(int nCount) %M&3VQ9w
{ =Ikg.jYq&F
nSplitter = nCount; kq-6HDR
} e"Rm_t
} DA"}A`HfI
@T&t.|`
-[R!O'N9
/* =MLf[
**Utility.java Y-p<qL|_
*/ \k@Z7+&7
package NetFox; dB;3.<S=
"&lN\&:
xd8 *<,Wj
public class Utility { )ofm_R'q*
#tjmWGo,
* OsU Y=;
public Utility() o>c^aRZ{
{ #SkX@sl@
TfRGA(+#
^Y04qeRd
} Ht[{ryTxu
MJ\[Dt
//线程睡眠 ?_q+&)4-o
public static void sleep(int nSecond) 9<s4yZF@x
{ ~]WVG@-
try{ <L2emL_'
Thread.sleep(nSecond); -2i\G.,J
} V5"HwN+`
catch(Exception e) 5PZN^\^
{ 6^#uLp>
e.printStackTrace (); s_eOcm
} /\=MBUN
} ]hE="z=n
4nkE IZ
//日志 v27Ja .tA
public static void log(String sMsg) _+w/ pS`M
{ %f&< wC
System.err.println(sMsg); .Q&rfH3
} I,O#X)O|i
:0^s0l
5j^NV&/_
public static void log(int sMsg) C3VLV&wF
{ :b/jNHJU
System.err.println(sMsg); sR=/%pVN
} k0H#:c}
} z.)p P'CJo
t FgX\4
n56;m`IU
/* I*\^,ow
**TestMethod.java "T6#
*/ D59T?B|BdD
package NetFox; PRs@zkO
QH@>icAb
.px:e)iW
public class TestMethod { onte&Ed\
)`HA::
1u}nm;3
public TestMethod() $Ui&D I
{ ///xx/weblogic60b2_win.exe .ve *Vp
try{ +MUwP(U=w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xxa} YIe8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O}Le]2'
SiteFileFetch fileFetch = new SiteFileFetch(bean); w'ybbv{c
fileFetch.start(); =%qEf
} @"|i"Hk^
catch(Exception e){e.printStackTrace ();} 9E1W|KE
IA*KaX2S<
x?r1s#88>
} eN-au/kN
BC/_:n8O
S>_27r{
public static void main(String[] args) 1BTIJ Gw
{ }zMf7<C
new TestMethod(); B|o%_:]+E
} >a>fb|r
} {0yu
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