http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); D%GGu"@GO
} -R@JIe_28f
for(int i=0;i<nEndPos.length-1;i++) ,^+#M{Z
{ 2E$i_jc
nEndPos = nStartPos[i+1]; 1E^{B8cm
} m3%ef
nEndPos[nEndPos.length-1] = nFileLength; x[}06k'
} E8;TLk4\
} El1:?4;
zPE#[\O21B
77_g}N
//启动子线程 ;siJ~|6)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +QupM
for(int i=0;i<nStartPos.length;i++) z6}Pj>1
{ Uf[T_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F(G<*lA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $:]tcY-L9
nStartPos,nEndPos,i); $nc, ?)i!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oYg/*k7EDX
fileSplitterFetch.start(); D3]@i&^B
} )T<D6l Lt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .r6YrB@['
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vu>YH)N_h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (JvQ-H
nEndPos = " + nFileLength); ox JGJ
// fileSplitterFetch[nPos.length-1].start(); |%3O)B
hqWPf
z-)*Q
//等待子线程结束 P[1m0!,B
//int count = 0; }RDb1~6C
//是否结束while循环 Z3I L8
boolean breakWhile = false; xK=J.>h3
IKtiR8
~e+0c'n\
while(!bStop) rkP4<E-M
{ q'fPNQg
write_nPos(); (-#rFO5~l
Utility.sleep(500); dd19z%
breakWhile = true; Cl-S=q@>V
G$S1#F -
WkcH5[
for(int i=0;i<nStartPos.length;i++) zdT->%
{ 6BR\iZ
if(!fileSplitterFetch.bDownOver) u[: P
{ t0I>5#*WU
breakWhile = false; lxCX-a`@p
break; K#iK6)tS
} #EEG>M*xB
} VEr 6uvB
if(breakWhile) kkHTbn=!
break; d{iL?>'?^
+H?<}N*T
QQSH +
//count++; Qlf 9]ug)
//if(count>4) SAQs{M
// siteStop(); Kyyih|{
} 3[,wMy"
lJ("6aT?
rS=tcBO
System.err.println("文件下载结束！"); c-ttds
} sio)_8tp
catch(Exception e){e.printStackTrace ();} }=xI3;7
} /bu'6/!`
KuU3DTS85Z
K:Mujx:
//获得文件长度 ,uKs>T^
public long getFileSize() v hR twi
{ o- cj&Cv%
int nFileLength = -1; X9DM^tt
try{ ?'TA!MR
URL url = new URL(siteInfoBean.getSSiteURL()); 3^j~~"2,w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y @]8Ep
httpConnection.setRequestProperty("User-Agent","NetFox"); DBLA% {05
|K'Gw}fX/
,^n-L&
int responseCode=httpConnection.getResponseCode(); 3j]UEA^
if(responseCode>=400) d.LOyO
{ Dl>*L
processErrorCode(responseCode); :h^O{"au^
return -2; //-2 represent access is error 3$MYS^D
} YG-Z.{d5Z
T$#FAEz
=I+l=;05Rd
String sHeader; d3\OHkM0^
9k(*?!\;
]u\`
for(int i=1;;i++) DxE^#=7iH;
{ 7=$+k]U8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); l6',
//Utility.log(in.readLine()); Y]D7i?3N
sHeader=httpConnection.getHeaderFieldKey(i); 3D]2$a_d
if(sHeader!=null) Mp]yKl
{ M@',3
if(sHeader.equals("Content-Length")) .vCY%0oE
{ ._8xY$l$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RPz!UMQSD
break; ;"d?_{>7
} 7Qm;g-)f
} =)mXCA^
else #Nu%]
break; ?ZSXoy-kr
} </K%i;l
} j;1~=j])
catch(IOException e){e.printStackTrace ();} a7XXhsZ
catch(Exception e){e.printStackTrace ();} Xtu:
/%N31
ws*~$x?7
Utility.log(nFileLength); Z/XM`Cy
(#fm (@T
ccHLL6F{
return nFileLength; H1aV}KD
} ?Zc/upd:$N
fW_}!`:
d~togTs1
//保存下载信息（文件指针位置） pDLu+}@
private void write_nPos() c n\k`8
{ gaLEhf^
try{ cq'}2pob
output = new DataOutputStream(new FileOutputStream(tmpFile)); XgwMppacw
output.writeInt(nStartPos.length); 6Tm Rc
for(int i=0;i<nStartPos.length;i++) \;3B?8wbIl
{ z5|e\Z
// output.writeLong(nPos); hLDch5J5~
output.writeLong(fileSplitterFetch.nStartPos); n"^/UQ|#j
output.writeLong(fileSplitterFetch.nEndPos); CT$& zEIm
} wGov|[X
output.close(); 1YF+(fk
} ?.rH;:9To
catch(IOException e){e.printStackTrace ();} hQd@bN8
catch(Exception e){e.printStackTrace ();} }}4sh5z
} 3{2^G@j
@%I_&!d
h"RP>fZt
//读取保存的下载信息（文件指针位置） 0?J|C6XM#4
private void read_nPos() E<X{72fb>
{ RTgQ#<W8
try{ IGh !d?D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d- Z+fz
int nCount = input.readInt(); 7- *(a
nStartPos = new long[nCount]; }[=xe(4]D
nEndPos = new long[nCount]; I =tyQ`
for(int i=0;i<nStartPos.length;i++) 'S%} ?#J
{ . Ce&9l
nStartPos = input.readLong(); }skRlC
nEndPos = input.readLong(); 0Y38T)k
} B9m>H=8a
input.close(); .-O@UQx.I
} 8%vh6$s6/
catch(IOException e){e.printStackTrace ();} ]Omb :
catch(Exception e){e.printStackTrace ();} okK/i
} avHD'zU}N
2yEO=SN,(
7\\~xSXh
private void processErrorCode(int nErrorCode) L5V'Sr
{ h a,=LV
System.err.println("Error Code : " + nErrorCode); A4 A6F<
} 5vUz
|1<]o;:
n!l./>N
//停止文件下载 \GbHS*\+
public void siteStop() q{9X.-]}
{ lgv-)5|O+H
bStop = true; ]]h:#A2
for(int i=0;i<nStartPos.length;i++) Y^94iOk%T
fileSplitterFetch.splitterStop(); @^y?Bh9jQ
=,>TpE
'Ec:l(2Ec
} @~!-a s7
} 6`s%%v
//负责部分文件的抓取 -A-hxK*^
**FileSplitterFetch.java </+%R"`
*/ !%Hl#Pv}
package NetFox; {LB }v;?l
9J2q`/6~e
9A*?E
import java.io.*; <.AC=4@V
import java.net.*; YjX!q]56
/]MB6E7&
V. bH$@ej
public class FileSplitterFetch extends Thread { n}9Msen
gvTOCF
!CVBG*E^l
String sURL; //File URL D_ Bx>G9
long nStartPos; //File Snippet Start Position O%fp;Y{`
long nEndPos; //File Snippet End Position }Pm(oR'KTJ
int nThreadID; //Thread's ID $_URXI
boolean bDownOver = false; //Downing is over :9!0Rm
boolean bStop = false; //Stop identical ulPrb>i
FileAccessI fileAccessI = null; //File Access interface LrM.wr zI/
evg7d
4U! .UNi
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "z#?OV5
{ 8[`^(O#\E
this.sURL = sURL; +/~\b/
this.nStartPos = nStart; ].<sAmL^
this.nEndPos = nEnd; z[|PsC3i:
nThreadID = id; |0%4Gk);
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $cJN9|$6
} avxn}*:X.
$)TF,-#x
k+q6U[ce
public void run() OnPy8mC
{ C)KtM YA,
while(nStartPos < nEndPos && !bStop) e??{&[
{ e`Zg7CaDd
f5=t*9_-[
4MtqQq4%
try{ c~L6fvS
URL url = new URL(sURL); B0oY]r6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s68_o[[E
httpConnection.setRequestProperty("User-Agent","NetFox"); i9EMi_%
String sProperty = "bytes="+nStartPos+"-"; LA=>g/+i.X
httpConnection.setRequestProperty("RANGE",sProperty); |IcxegE
Utility.log(sProperty); Y?vm%t`K
Fzld0p9=
dE}b8|</
InputStream input = httpConnection.getInputStream(); Y="&|c=w#L
//logResponseHead(httpConnection); EYx2IJ
q5\LdI2
:oj) eS[Y
byte[] b = new byte[1024]; "<.
int nRead; ?k:])^G5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Er/5 ,
{ 'd.@4 9
nStartPos += fileAccessI.write(b,0,nRead); t0V_ c'm
//if(nThreadID == 1) }DUDA%U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); " ;R3260
} 3@cJ=
M%5$-;6~_
g7U:A0Z
Utility.log("Thread " + nThreadID + " is over!"); o4[2`mT
bDownOver = true; 18/@:u{
//nPos = fileAccessI.write (b,0,nRead); M(h H#_$
} \2<yZCn
catch(Exception e){e.printStackTrace ();} mN'9|`>V>
} n8OdRv
} w)m0Z4*
k>0cTBY&
<<2b2?aS`
//打印回应的头信息 P7x?!71?L
public void logResponseHead(HttpURLConnection con) V\M!]Nnxr
{ 'y M:WcN
for(int i=1;;i++) ^Lfn3.M
{ U_{JM`JY
String header=con.getHeaderFieldKey(i); CU>K
if(header!=null) k+R?JWC:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /L|}Y242
Utility.log(header+" : "+con.getHeaderField(header)); <9@]|
else 4tTZkJc
break; q'V{vFfY%
} ot+~|Dl
} [rQ(ae
wIR[2&b
"xc*A&Sg
public void splitterStop() gAUQQ
{ 1707
bStop = true; Z8dN0AqZ
} ]>4Qs
(Nlm4*{h
'lRHdD}s
} _TN$c
&|{,4V0%A
yzNX2u1
/* ]ifHA# z`~
**FileAccess.java D_ZBx+/_?
*//文件访问(定位，写) A-wxf91+:
package NetFox; OI}HvgV^!
import java.io.*; MW[ 4^
yoY)6cn@
"A1yqK
public class FileAccessI implements Serializable{ U}wq~fD
-Lf6]5$2'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =]xk-MY"|R
RandomAccessFile oSavedFile; VUv.Tx]Z[
long nPos; >(6\ C
rnhf(K.{3
75}u D
public FileAccessI() throws IOException YxkEAb!+
{ KP7RrgOan&
this("",0); ?ZV0
} i|,A1c"*
_>m*`:Wb
|M/ \'pOe
public FileAccessI(String sName,long nPos) throws IOException PZhZK VZx
{ OK J%M]<
oSavedFile = new RandomAccessFile(sName,"rw"); XXwhs-:o
this.nPos = nPos; q vVZA*
oSavedFile.seek(nPos); z+D,:!yF
} 5'-9?-S"
I2lZ>3X{
P~ZV:Of
public synchronized int write(byte[] b,int nStart,int nLen) ~kJpBt7M
{ wXZY5-h4
int n = -1; KC-aLq/
try{ kGqf@ I+
oSavedFile.write(b,nStart,nLen); ,L:)ZZgN
n = nLen; h_G7T1;L
} (dipKs?K
catch(IOException e) # +]! u%n
{ V1>94/waa
e.printStackTrace (); *Z2Q]?:{ i
} nkj'AH"2
842+KLS
2b,TkG8K
return n; @Be:+01z
} aw"%B-N\
/aa;M*Qp
q.QYn.CBZz
} Iw|[*Nu-
>T^v4A
r8?Lr-;
/* : 8<^rP
**SiteInfoBean.java X/7_mU>aKT
*/ wP1VQUL
package NetFox; CgKSK0/a
?N*@o.
p2vUt
public class SiteInfoBean { sx^? Iw,N'
9S1V!Jp
64>[pZF8
private String sSiteURL; //Site's URL w&cyGd D5
private String sFilePath; //Saved File's Path uBkny;
private String sFileName; //Saved File's Name xa0%;nFKe
private int nSplitter; //Count of Splited Downloading File TXl9c6
c]R![sa
3&Rqz9W
public SiteInfoBean() B[|/wHMsT}
{//nSplitter的缺省值为5 $K fk=@
//default value of nSplitter is 5 76r s)J[*w
this("","","",5); F_Cz
} _-\{kJ
&LQab>{*K
TC#B^m`'p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2U+p@}cQUA
{ Ol[IC
sSiteURL= sURL; D?F5o^e"h<
sFilePath = sPath; m8^2k2
sFileName = sName; H=RV M
this.nSplitter = nSpiltter; &D w~Jq|
]~Qkg+>'&
/iuNdh
} GZX!iT
~(]DNXB8I`
,ToEKId
public String getSSiteURL() 8HA=O?Cg
{ j5^b~F%
return sSiteURL; M':.b+xN
} ZSt ww{Z
B8Zd#.6]
*bSG48W("
public void setSSiteURL(String value) ~At.V+
{ 'oL[rO~j
sSiteURL = value; Li^!OHro.
} c6)zx b
kxwm08/|f
<!>}t a
public String getSFilePath() %~2m$#)
{ ^v|!(h\ZC
return sFilePath; Hv*O9!cC
} 'Pu;]sC
|YFlJ2w
uhLmyK
public void setSFilePath(String value) bC-x`a@
{ }TL"v|ny6;
sFilePath = value; Tou~U[V+
} hI{Yg$H1
3U$fMLx]k
xyz86r ^u
public String getSFileName() v72 dE
{ 7Z3qaXPH
return sFileName; ,SwaDWNO
} <);u]0
Ec 7M'~1
)yZE>>3-
public void setSFileName(String value) >GUTno$J
{ >@uYleD(
sFileName = value; ]#.#]}=
} K$]B" s
e90z(EF?0
{ rn~D5R
public int getNSplitter() 1*jm9])#
{ iL1so+di
return nSplitter; ,[#f}|s_
} s%|J(0
nHjwT5Q+Q
gMn)<u>
public void setNSplitter(int nCount) jQ}|]pj+
{ sTyGi1
nSplitter = nCount; /^G+vhlf\
} ~vFo 0k(
} a$8?0`(
b] V=wZ o
@7'gr>_E
/* B=|sLs`I
**Utility.java Hefqzu
*/ {!h[@f4
package NetFox; 3om-,gfZ
jqedHnx
}3lF;k(2g
public class Utility { 7yl'!uz)9
92Iv'(1ba
"O "@HVF@
public Utility() f}eVfAf
{ 5GkM7Zu!{j
kGP?Jx\PkH
6suc:rp";
} .`XA6e(8KR
$@;[K\
//线程睡眠 IRa*}MJe
public static void sleep(int nSecond) {*9i}w|2
{ K? k`U,
try{ ?VsZo6Z"
Thread.sleep(nSecond); +%v4Ci"%y
} ;7>--_?=
catch(Exception e) 5Ncd1
{ iI0'z=J
e.printStackTrace (); \-yi#N
} "(qO}&b>
} my6T@0R
(eP)>G]
//日志 t:7jlD!d
public static void log(String sMsg) WgB,,L,
{ owhht98y(
System.err.println(sMsg); Rim}DfO/
} !ZW0yCwLQ
Y~!@
>2/zL.O
public static void log(int sMsg) mgWtjV 8
{ jXf-+;ZQ
System.err.println(sMsg); W+X zU"l
} 5hMiCod
} )j'b7)W\
&IYkeGQr
}I]q$3.
/* {5h_$a!TaU
**TestMethod.java (%Rs&/vU~
*/ ~fe0Ba4
package NetFox; 3Y8 V?* 1|
Z#04 ]
Tw5BvB1
public class TestMethod { }s[/b"%y
]\U'_G2]
\Wk$>?+#@
public TestMethod() aXagiz\;
{ ///xx/weblogic60b2_win.exe Wwz{98,K
try{ (x@"Dp=MZW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =[&Jxy>Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); </QSMs
SiteFileFetch fileFetch = new SiteFileFetch(bean); .9ne'Ta
fileFetch.start(); *#_jTwQe
} S0`*
catch(Exception e){e.printStackTrace ();} MNzq}(p
",m5}mk:4
14R))Dz"
} r[~$
.B*)A.
sBwgl9
public static void main(String[] args) Ih0GzyU*4
{ ^8iy(
new TestMethod(); ITV}f#
} hGeRM4zVZZ
} vY6|V$
点击下载更多相关资料