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)); +2>, -V
} .EZ8yJj1Q
for(int i=0;i<nEndPos.length-1;i++) ssAGWP
{ ?(M$r\\
nEndPos = nStartPos[i+1]; baGV]=j
} `jec|i@oO
nEndPos[nEndPos.length-1] = nFileLength; .|0$?w
} ^%O$7*
} <Ok7-:OxA
}U?:al/m
=^z*p9ZB
//启动子线程 *onVG5<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mbHMy[R
for(int i=0;i<nStartPos.length;i++) g){gF(
{ f9t+x+ Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I#;.;%u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3gYtu-1
nStartPos,nEndPos,i); <?h(Dchq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~:*V'/2k
fileSplitterFetch.start(); #vc!SI
} MzF,is
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F~/~_9RJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rpc;*t+z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F^&@[k7WW
nEndPos = " + nFileLength); DABV}@K"
// fileSplitterFetch[nPos.length-1].start(); BwAmNW&i
{vk%&{D0)
N'0nt]&a
//等待子线程结束 \H 5t-w=
//int count = 0; 8%p+:6kP5
//是否结束while循环 ),H1z`c&I
boolean breakWhile = false; E:;MI{;7
~MP/[,j`
EqOhzII^
while(!bStop) &yI>A1
{ zb s7G
write_nPos(); VVfTFi<
Utility.sleep(500); 9%2he)Yqc
breakWhile = true; 92~$Qa\S!
ZCA= n
@2`nBtk
for(int i=0;i<nStartPos.length;i++) ng9_c
{ Wu/:ES)C
if(!fileSplitterFetch.bDownOver) u+c2 m
{ z\YLO%Mm
breakWhile = false; Mm!;+bM%
break; -s\R2_(
} uQKo2B0
} QcX&q%*0
if(breakWhile) v1/Y0
break; /#SH`ZK
1GPBqF
"LH3ZPD
//count++; /S@iF
//if(count>4) R G~GVf
// siteStop(); di7cCn
} x6ayFq=
5Q:%f
&da:{
System.err.println("文件下载结束！"); 7>F[7_
} .3#Xjhebvu
catch(Exception e){e.printStackTrace ();} `aA)n;{/2u
} %'VzN3Q5V
J&B5Ll
I9xkqj
//获得文件长度 ?!.J0q
public long getFileSize() bdEIvf7
{ lqa~ZF*
int nFileLength = -1; !pHI`FeAV
try{ "sWsK %
URL url = new URL(siteInfoBean.getSSiteURL()); /FjdcH=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G-,0mo
httpConnection.setRequestProperty("User-Agent","NetFox"); TD78&a#
jvpv1>KYV
S,Q(,e^&
int responseCode=httpConnection.getResponseCode(); `fl$ o6S/
if(responseCode>=400) 3Bcv"O,B!{
{ A`"?~_pHC
processErrorCode(responseCode); 4YoQ*NQw-
return -2; //-2 represent access is error AUES;2WL
} oE2VJKs<B
8L]Cc!~
:B\$7+$v
String sHeader; (Ffa{Tt!
4~8-^^
TX7dwmt)N
for(int i=1;;i++) sHPj_d#
{ s'OK])>`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EVE"F'Ww,_
//Utility.log(in.readLine()); (*,R21<%
sHeader=httpConnection.getHeaderFieldKey(i); e_g&L)
if(sHeader!=null) ux,eY
{ \rE] V,,2
if(sHeader.equals("Content-Length")) U#<{RqY
{ ?mN!9/DIc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yo%Nz"
break; :^`WrcOJ
} FYb]9MX
} d[nz0LI|mk
else U* uMMb}$
break; 1&vR7z]*
} `wr*@/P
} #%L_wJB-
catch(IOException e){e.printStackTrace ();} ej1WkaR8
catch(Exception e){e.printStackTrace ();} B?Rkz
s,l*=<
BuUM~k&SY
Utility.log(nFileLength); T0.sL9
e E(+
"z=~7g
return nFileLength; t:xTmK&vt
} 8 qZbsZi4
=k;X}/
OMd:#cWsQ
//保存下载信息（文件指针位置） (+<66 TO
private void write_nPos() MBnxF^c&P
{ /LtbmV
try{ Sz]1`%_H/
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4W<[& )7
output.writeInt(nStartPos.length); 7#X`D
for(int i=0;i<nStartPos.length;i++) [Z&<# -
{ J)|I/8!#
// output.writeLong(nPos); t:v>W8N53
output.writeLong(fileSplitterFetch.nStartPos); 2izBB,# "
output.writeLong(fileSplitterFetch.nEndPos); 4ElS_u^cP7
} C~'.3Q6
output.close(); 'pO-h,{TS
} [fELf(;(
catch(IOException e){e.printStackTrace ();} V|*3*W
catch(Exception e){e.printStackTrace ();} [57`V&c5
} UIU6rilB
8@|{n`n]
>%slzr
//读取保存的下载信息（文件指针位置） }o\} qu*
private void read_nPos() 6Q{OM:L/;.
{ mS49l
try{ HiD%BL>%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $BG]is,&5
int nCount = input.readInt(); 91DevizXx
nStartPos = new long[nCount]; z46Sh&+
nEndPos = new long[nCount]; } :gi<#-:G
for(int i=0;i<nStartPos.length;i++) =h+-1zp{M^
{ =kzHZc
nStartPos = input.readLong(); U-U(_W5&
nEndPos = input.readLong(); kf#S"[/E
} +ZFN8
input.close(); M&sQnPFH
} NLUO{'uUW
catch(IOException e){e.printStackTrace ();} P{Q$(rOe
catch(Exception e){e.printStackTrace ();} *i!t&s
} ] ;HCt=I~
J4 U]_|
Hw62'%
private void processErrorCode(int nErrorCode) dxH.
{ y(E<MRd8V
System.err.println("Error Code : " + nErrorCode); Z|)1ftcC
} V 'fri/Z
8Z)wot
NS;LFeGD
//停止文件下载 bfpoX,:
public void siteStop() ':DL
{ -.L )\
bStop = true; FIu^Qd
for(int i=0;i<nStartPos.length;i++) a4Z e!l(
fileSplitterFetch.splitterStop(); 2Uu!_n}tNF
KuL+~
"|R75m,Id
} ic l]H
} =EU;%f
//负责部分文件的抓取 zZey
**FileSplitterFetch.java d#W^S[[
*/ Lf%}\0:
package NetFox; ,4B8?0sH|
bQ&%6'ck
pd.unEWwF
import java.io.*; )h{+pK
import java.net.*; kpNp}b8']
tZFpxyF
'Asr,[]?
public class FileSplitterFetch extends Thread { 0F%?<: &
yL -}E
O`aNNy
String sURL; //File URL \MPbG$ ^
long nStartPos; //File Snippet Start Position o` dQ
long nEndPos; //File Snippet End Position sI09X6)
int nThreadID; //Thread's ID $Zkk14
boolean bDownOver = false; //Downing is over bf2r8
boolean bStop = false; //Stop identical PzhC *" i}
FileAccessI fileAccessI = null; //File Access interface ]v?jfy
AS[j)x!
C}DIm&))
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1TF S2R n
{ BHErc\ITP
this.sURL = sURL; }OTJ{eG
this.nStartPos = nStart; {wDe#c{_
this.nEndPos = nEnd; <Of-,PcCV
nThreadID = id; v!$?;"d+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wM3m'# xJ
} @Pi]kWW})
2^w{Hcf
.[3C
public void run() Z%=A[`5]
{ 5w+&plIJ
while(nStartPos < nEndPos && !bStop) c~OvoTF,
{ kLpq{GUv:
PSX o"
nV`W0r(f'
try{ _N>#/v)Yi
URL url = new URL(sURL); @ `mke4>_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >hV2p/D
httpConnection.setRequestProperty("User-Agent","NetFox"); VWzuV&;P
String sProperty = "bytes="+nStartPos+"-"; b):aqRwP
httpConnection.setRequestProperty("RANGE",sProperty); ;18u02z^
Utility.log(sProperty); /Ei e5p
9\=SG"e(
ELG9ts+5Uj
InputStream input = httpConnection.getInputStream(); G%= gCR
//logResponseHead(httpConnection); (hIo0.
9]1LwX!M2
*X}2
byte[] b = new byte[1024]; s#")hMJQ
int nRead; D(&WEmm\B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F~bDg tN3
{ Kc#1H|'2N
nStartPos += fileAccessI.write(b,0,nRead); `R-?+76?
//if(nThreadID == 1) U3UA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '#.D`9YI<
} tDfHO1pS
475g-t2"@
XD_!5+\H1
Utility.log("Thread " + nThreadID + " is over!"); h^''ue"
bDownOver = true; W )Ps2
//nPos = fileAccessI.write (b,0,nRead); i&DUlmt)f
} Gi2Fjq/Y
catch(Exception e){e.printStackTrace ();} *Tr{a_{~C
} 8F's9c,
} } j;es(~D
mG0_&'"YIG
m&be55M;
//打印回应的头信息 3"k n5)x
public void logResponseHead(HttpURLConnection con) 6K=}n] n
{ #uCfXJ-
for(int i=1;;i++) % I2JS
{ gFfKK`)}D'
String header=con.getHeaderFieldKey(i); \ Z5160
if(header!=null) peOoZdJd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =A$d)&
Utility.log(header+" : "+con.getHeaderField(header)); *19a\m=>oi
else q9a6s{,
break; sOS^
} DnW/q
} &FYv4J
`~41>mM%
&!M6{O=~
public void splitterStop() Rtl1eJ-
{ JeA_mtSQ|
bStop = true; 036QV M$
} bqx2lQf,_
HEhBOER?
)p:+!sX(
} S;%k?O7v
`9P`f4x
b@K1;A! S
/* }qZ^S9
**FileAccess.java P6=5:-Hh
*//文件访问(定位，写) ^),t=!;p
package NetFox; YRd`G3J
import java.io.*; >RpMw!NT
k72NXagh
-7%dgY(
public class FileAccessI implements Serializable{ R|Uu
r)Ml-r=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _u6MSRX[6$
RandomAccessFile oSavedFile; iU3PlF[B/o
long nPos; RUVrX`u*(
bUSa#pNO>
W{j(=<|<
public FileAccessI() throws IOException N%e^2O)
{ ]&P 4QT)f
this("",0); *Ue#Sade
} 2:e7'}\D.
CteNJBm
|Z+qaq{X
public FileAccessI(String sName,long nPos) throws IOException Py/~Q-8p
{ 8=?U7aw
oSavedFile = new RandomAccessFile(sName,"rw"); t3K9 |8<
this.nPos = nPos; (*V!V3E3#
oSavedFile.seek(nPos); Ap|g[J
} (<}?}{YX0
L&uPNcZ`-
_?$w8 S%
public synchronized int write(byte[] b,int nStart,int nLen) =e9<.{]S/
{ v!3Oq.ot
int n = -1; F|o1r
try{ NdXC8
oSavedFile.write(b,nStart,nLen); IH5^M74b
n = nLen; d5R2J:dI
} %Q;:nVt
catch(IOException e) ,\d03wha
{ eW}-UeT
e.printStackTrace (); sN5Mm8~
} +~M.VsX
?Jgqb3+!o
C 20VSwd
return n; 8E9k7
} CoWT
JRAU|gr
4E1j0ARQQ
} T eu.i
iQLP~Z>,T
X\*H7;k,
/* "1%k"+&
**SiteInfoBean.java <DII%7q,6/
*/ PGVP0H+RV
package NetFox; U#XW}T=|
l\d[S]
E33x)CP
public class SiteInfoBean { ng6E&<Z
yC4%z)t&R
frV_5yK'
private String sSiteURL; //Site's URL w=0zVh_`(
private String sFilePath; //Saved File's Path G(t&(t`[
private String sFileName; //Saved File's Name t~!ag#3['.
private int nSplitter; //Count of Splited Downloading File Y|W#VyM-
Ln/*lLIOb
/sPa$D
public SiteInfoBean() ]g,j
{//nSplitter的缺省值为5 w]N;HlU
//default value of nSplitter is 5 O<dCvH
this("","","",5); 1W}k>t8?h'
} k ,r*xt
st#^pWL
r|/9'{!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q trU_c2k
{ XjxI@VXzUV
sSiteURL= sURL; vVsaGW
sFilePath = sPath; =eh!eZ9
sFileName = sName; k RSY;V
this.nSplitter = nSpiltter; BV\~Dm]"
:X7O4?ww
2|`Mb~E;
} s=z$;1C
u~mpZ"9$ 3
I+jc
public String getSSiteURL() |O"Pb`V+
{ 'gsO}xj
return sSiteURL; {e0aH `me
} !thFayq
'kg~#cf/+
U2\k7I
public void setSSiteURL(String value) H;Gs0Qi;
{ Lu[Hz8
sSiteURL = value; v^[!NygShs
} l SuNZYaO
DLe>EU;vS
]xIgP%
public String getSFilePath() c]ga)A(
{ ww'B!Ml>F
return sFilePath; ,I,Zl.5
} [g+WL\1
=OKUSHu@V
i"E_nN"V
public void setSFilePath(String value) {~w!
{ xZloEfv.B
sFilePath = value; U-{3HHA
} S>"C}F$X
@]EdUzzKq
E|6@h8#
public String getSFileName() @9k/od@mW
{ \Z~ <jv
return sFileName; vJ&35nF&
} N2u4MI2
$ylxl"Y
4(,X.GVY/
public void setSFileName(String value) >F/E,U ]
{ hWX4 P
sFileName = value; ;B:\e8
} .l,NmF9
*_ajb:
1D~B\=LL}
public int getNSplitter() 'w|N} 4
{ M?['HoRo
return nSplitter; s(MdjWw
} 90H/Txq
Lr`Gyl62
wvr`~e
public void setNSplitter(int nCount) -W|~YK7e
{ [[}ukG4
nSplitter = nCount; -,$:^4
} oiz]Bd
} 1Va@w
li}>xDSQ4
*r6v9
/* ZalL}?E ?
**Utility.java J%E0Wd
*/ clIn}wQ
package NetFox; X{h[
I7<UC{Ny
;N _%O
public class Utility { oV~S4|9:
wFBSux$
4@M}5WJ7
public Utility() B{V(g"dM
{ %XXjQ5p
aZta%3`)
a6/ETQ
} LM!@LQAMY
!VvM
//线程睡眠 `0R>r7f)H
public static void sleep(int nSecond) b1Ba}
{ f>?b2a2HX
try{ ` ^z l =
Thread.sleep(nSecond); of`WP
} 3BB/u%N}
catch(Exception e) yv> 6u7
{ ]:4\rBR3
e.printStackTrace (); @ZcI]G%
} !zfV(&
} j<L!(6B
O%Qz6R
//日志 sWP_fb1
public static void log(String sMsg) |j$$0N
{ 8: VRq
System.err.println(sMsg); ~jC$C2A0
} &Hl w2^
ZP.~Y;Ch;-
+n|@'= ]
public static void log(int sMsg) }O6E5YCm
{ 9;A9Q9Yr
System.err.println(sMsg); !1bATO:x
} +1Rz+
} e&9v`8}
!@ )JqF.
2W)KfS
/* )fc+B_
**TestMethod.java ' KNg;
*/ `Z (`
package NetFox; Ja%isIdh
X@~R<
z+nq<%"'
public class TestMethod { hOm0ND?;1
ZVCa0Km
D#X&gE
public TestMethod() (i]0IYMXy*
{ ///xx/weblogic60b2_win.exe z+Ej`$E{lD
try{ {=P}c:iW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); iDlg>UYd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q9(hn_X@/
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1_)Y{3L
fileFetch.start(); |eej}G(,m}
} sTi3x)#xB
catch(Exception e){e.printStackTrace ();} #-g2p?+i&
HU-#xK
:2;c@ uj
} -L2%,.E>4
zY&/lWW._
I -V=Z:
public static void main(String[] args) z*/}rk4i
{ &3YXDNm
new TestMethod(); twql)lbx
} va;fT+k=
} s&-dLkis{u
点击下载更多相关资料