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)); F :u}7t>
} sK\?i3<?
for(int i=0;i<nEndPos.length-1;i++) _])1P?.
{ y|@^0]}%<
nEndPos = nStartPos[i+1]; H(pOR<`
} 0trFLX
nEndPos[nEndPos.length-1] = nFileLength; ';1 c
} UpgOU.
} nyIb8=f
n\ IVpgP
YB 4R8}4
//启动子线程 q)P<lKi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $/D@=Pkc
for(int i=0;i<nStartPos.length;i++) _ pJU~8
{ qYpHH!!C=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x[vX|oE!A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mU3UQ j
nStartPos,nEndPos,i); )QX9T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %(NRH?
fileSplitterFetch.start(); 6@T_1
} Y`M.hYBXk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^iGIF~J9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S4|)N,#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S`J_}>
nEndPos = " + nFileLength); BFMM6-Ve
// fileSplitterFetch[nPos.length-1].start(); VC.r
nZ{~@E2
MM97$
//等待子线程结束 v!x=fjr<
//int count = 0; p@!"x({@l
//是否结束while循环 im&|H-
boolean breakWhile = false; ue`F|
>LW9$[H
~[[a7$_4
while(!bStop) .$q]<MK8
{ `dj/Uk
write_nPos(); _ p?q/-[4
Utility.sleep(500); {}>"f]3
breakWhile = true; sx/g5?zh
72PDqK#
SkK=VeD>8
for(int i=0;i<nStartPos.length;i++) e\P+R>i0
{ UWu|w
if(!fileSplitterFetch.bDownOver) #a/lt^}C*
{ ~:JKXa?
breakWhile = false; 08'JT{iid
break; sT/pA^rnnR
} >8RIMW2
} "r[Ea|
if(breakWhile) tmm\V7sJ
break; p1 o?^A&
wo?C7,-x
[rQ#skf
//count++; V,>#!zUv
//if(count>4) / {A]('t
// siteStop(); BkIvoW_
} "Uyw7
p<jHUG4?'
:}E*u^v K
System.err.println("文件下载结束！"); '2%hc\P6P
} _/KW5
catch(Exception e){e.printStackTrace ();} vK6bpzI 3
} OnG!5b
ag] nVE/
R z[-
//获得文件长度 ~M <4HC
public long getFileSize() 7C&`i}/t
{ #!<x|N?_<
int nFileLength = -1; u'=#~'6
try{ SK-|O9Ki
URL url = new URL(siteInfoBean.getSSiteURL()); q6osRK*20
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K7CiICe
httpConnection.setRequestProperty("User-Agent","NetFox"); xvgIYc{
N'^ 0:zK:
[V1gj9t=,
int responseCode=httpConnection.getResponseCode(); YrB-;R1+
if(responseCode>=400) >(\[$
{ h>\}-|Ek
processErrorCode(responseCode); !FO92 P16
return -2; //-2 represent access is error 0wOgQ n
} dso\+s
zO!`sPP
A]R"C:o
String sHeader; BL]^+KnP
E6n;_{Se/S
>q]r)~8F^
for(int i=1;;i++) NMOTWA}2
{ xNjA>S\]W5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L*FnFRhU
//Utility.log(in.readLine()); d*H-l3N
sHeader=httpConnection.getHeaderFieldKey(i); 8o~\L= l
if(sHeader!=null) _msDf2e9
{ TN l$P~X>
if(sHeader.equals("Content-Length")) GifD>c |z
{ ]bRu8kn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LxMOs Nv
break; bG\1<:6B
} {0e5<"i
} !vG._7lPp
else h7o{l7`)
break; 1P6~IZVN
} YP#OI6u
} 0{Tf;a<
catch(IOException e){e.printStackTrace ();} CMTy(Z8_)
catch(Exception e){e.printStackTrace ();} |rNm_L2
S>**hMU%
HI:E&20y
Utility.log(nFileLength); b"x:IDW qG
<01MXT-
az`5{hK
return nFileLength; 15SIZ:Q
} w$2-t
\2~.r/`1
's*UU:R
//保存下载信息（文件指针位置） DNL TJrN
private void write_nPos() _&yQW&vH#
{ QAu^]1;
try{ D:){T>
output = new DataOutputStream(new FileOutputStream(tmpFile)); HLk/C[`u,
output.writeInt(nStartPos.length); W&rjJZY6
for(int i=0;i<nStartPos.length;i++) {9P<G]Z
{ bXtA4O
// output.writeLong(nPos); K)^.96{/@
output.writeLong(fileSplitterFetch.nStartPos); }LE.kd&
output.writeLong(fileSplitterFetch.nEndPos); 7O"T`>
} qo'pU/@
output.close(); 23Eg|Xk
} +y-:(aP
catch(IOException e){e.printStackTrace ();} :<nL9y jt
catch(Exception e){e.printStackTrace ();} bv|v9_i
} CVu'uyy
@ '<lD*W
=. OWsFv
//读取保存的下载信息（文件指针位置） *r(iegO$
private void read_nPos() $KtMv +m"
{ .t\Yv/|`
try{ igz&7U8gg
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r Cmqq/hZ
int nCount = input.readInt(); ysvn*9h+&
nStartPos = new long[nCount]; >2N`l
nEndPos = new long[nCount]; <$ '#@jW
for(int i=0;i<nStartPos.length;i++) ]\Ez{MdAT
{ 3`-[95w
nStartPos = input.readLong(); |n]^gTJt
nEndPos = input.readLong(); oq;}q
} tXfB.[U
input.close(); {K:/(\
} 8B\,*JGY2
catch(IOException e){e.printStackTrace ();} 3):7mE(
catch(Exception e){e.printStackTrace ();} qB"y'UW8
} i"_JF-IbN
r\L:JTZ$
GVFD_;j'
private void processErrorCode(int nErrorCode) bx`(d@
{ W*VQ"CW{^]
System.err.println("Error Code : " + nErrorCode); >N44&W
} ? BBDk
8vnU!r
VRMlr.T+
//停止文件下载 '?Hy"5gUA
public void siteStop() M}us^t*
{ qOkw6jfluh
bStop = true; mVk:[ }l6
for(int i=0;i<nStartPos.length;i++) JCE364$$"
fileSplitterFetch.splitterStop(); ,{YC|uB
P`RM"'Om
GAPZt4Z2
} mo<g'|0
} hZ$* sf
//负责部分文件的抓取 l*pCG`@J#
**FileSplitterFetch.java mnG\UK,k
*/ `/Z8mFs Y
package NetFox; {T.$xiR
A:k`Ykr[
#]n[
import java.io.*; %M~Ugv_4v
import java.net.*; I]TL#ywF
vUJb-
{:fyz#>>^
public class FileSplitterFetch extends Thread { Fa@#nY|UV3
&a1agi7M
DlTV1X-^1
String sURL; //File URL 8+`cv"
long nStartPos; //File Snippet Start Position Qb9) 1
long nEndPos; //File Snippet End Position vzs6YsA
int nThreadID; //Thread's ID )WuuU [(
boolean bDownOver = false; //Downing is over r+\it&cW+
boolean bStop = false; //Stop identical g5/8u2d
FileAccessI fileAccessI = null; //File Access interface R],,-
|0mh*+i
33-=Z9|r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wG19NX(
{ 4W$53LP8
this.sURL = sURL; |yw-H2k1
this.nStartPos = nStart; Hk$|.TjzI
this.nEndPos = nEnd; RrGS$<
nThreadID = id; _MnMT9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^> ZQ:xs@(
} qo4AQ}0 <
: 8(~{<R
o"TEmZUP
public void run() Y`\zLX"_m
{ IjD: hR@
while(nStartPos < nEndPos && !bStop) H=7dp%b"
{ z_r W1?|
%k1*&2"1#
^!E;+o' t
try{ :P;#Y7}Y$
URL url = new URL(sURL); r=8]Ub[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +qjW;]yxP
httpConnection.setRequestProperty("User-Agent","NetFox"); nM\Wa
String sProperty = "bytes="+nStartPos+"-"; Hq6VwQu?
httpConnection.setRequestProperty("RANGE",sProperty); 7{/qQGL
Utility.log(sProperty); Z A7u66
2.?:[1g!
UV@<55)K
InputStream input = httpConnection.getInputStream(); ?RrJYj1
//logResponseHead(httpConnection); Za4 YD
C n4|qX"&t
U#@:"v|
byte[] b = new byte[1024]; Qy$8!(
int nRead; >aN@)=h}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %[;<'s5e~
{ < _c84,[V
nStartPos += fileAccessI.write(b,0,nRead); 6'|J ;
//if(nThreadID == 1) [,xFk* #
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S &cH1QZ
} \>1M?
kMN z5P
]qhVxeUm
Utility.log("Thread " + nThreadID + " is over!"); *)g*5kKN
bDownOver = true; ]!0 BMZmf
//nPos = fileAccessI.write (b,0,nRead); st'Y j
} ZVgR7+`]#
catch(Exception e){e.printStackTrace ();} 5as';1^P&*
} HwM:bY N
} ~"+[VE5
RSzp-sKB
E8#y9q
//打印回应的头信息 j3sUZg|d
public void logResponseHead(HttpURLConnection con) q>!T*BQ
{ m <aMb
for(int i=1;;i++) &A=d7ASN=
{ uqX"^dn4u
String header=con.getHeaderFieldKey(i); <f8@Qij
if(header!=null) Z37Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =@w};e#D
Utility.log(header+" : "+con.getHeaderField(header)); A3!NEFBK
else iTqv=
break; Ba!`x<wa
} 2ggW4`"c
} /.7x[Yc
pl|<g9
mS!/>.1[
public void splitterStop() +~8/7V22
{ B=|yjA'Fg
bStop = true; tAbIT;>
} -D38>#Y
Tb:n6a@
Xqf"Wx(X
} nPvR
1[u{3lQ
$5%tGFh
/* %D e<H*
**FileAccess.java \'BKI;
*//文件访问(定位，写) qd!$nr
package NetFox; |;9OvR> A
import java.io.*; 2!{CNt.-
[@Uc4LX
u&2uQ-T0
public class FileAccessI implements Serializable{ lt5~rH2
ag[yM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 khc5h^0
RandomAccessFile oSavedFile; \muyL?
long nPos; B~LB^ n(>@
-wvJZ
b>Vs5nY!
public FileAccessI() throws IOException _aa3Qwx
{ !i#;P9K
this("",0); V@e0VV3yx%
} /rKrnxw
1B,RRHXn6
Kd7OnU
public FileAccessI(String sName,long nPos) throws IOException Ca?pK_Y
{ AO>K 6{
oSavedFile = new RandomAccessFile(sName,"rw"); C0KP,JS&
this.nPos = nPos; *kZJ
oSavedFile.seek(nPos); O:p~L`o>>
} AkT_ZU>
m'z<d
+%'0;
public synchronized int write(byte[] b,int nStart,int nLen) g&riio7lx
{ T~`m'4"+c
int n = -1; tUz!]P2BUO
try{ -%%2Pz0I
oSavedFile.write(b,nStart,nLen); N@;6/[8
n = nLen; r|?2@VE
} [eG- &u
catch(IOException e) > YN<~z-
{ Tet,mzVuu
e.printStackTrace (); YNk?1#k?i
} ?Za1 b
QP[w{T
CNfeHMT
return n; kmo3<'j{
} n8R{LjJ2@
RHVMlMX
W#-M|
} F-UY~i8
%|l*=v
Wa,[#H
/* _2U1$0xK
**SiteInfoBean.java |/YT.c%
*/ FkKx~I:
package NetFox; |w:7).P
]U'KYrh
DQKhR sC
public class SiteInfoBean { LD]XN'?"W
gd/W8*NFR
Ur]5AJ
private String sSiteURL; //Site's URL 9K FWa0G
private String sFilePath; //Saved File's Path L!-T`R8'c
private String sFileName; //Saved File's Name \CU.'|X
private int nSplitter; //Count of Splited Downloading File -DU[dU*~
'OkF.bs
CW, Kw
public SiteInfoBean() l(%bdy
{//nSplitter的缺省值为5 spd>.Cm`
//default value of nSplitter is 5 ?ry`+nx
this("","","",5); #LBZ%%v
} !63x^# kg
9J0m
;Fp"]z!Qh+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '.d el7s
{ au0)yg*V1
sSiteURL= sURL; >qAQNX
sFilePath = sPath; NWv1g{M
sFileName = sName; ,%>/8*
this.nSplitter = nSpiltter; LT#*nr
6W#M[0
M nH4p
} ~hYG%
0j_`7<,:
a|lcOU
public String getSSiteURL() 3 LoB-4u?
{ W}a&L
return sSiteURL; cFD(Ap
} PHZA?>Q7Z
}3=]1jH6
),dXaP[
public void setSSiteURL(String value) R279=sO,J
{ d,+d8X
sSiteURL = value; h-Ffs
} VmV/~-<Z
!W .ooy5(
m~#98ZJ^
public String getSFilePath() h]vA%VuE'E
{ !);'Bk9o
return sFilePath; Ba6''?;G
} ([tbFI}A
~48Uch\LG:
>/ W:*^g)
public void setSFilePath(String value) 0rjxWPc
{ 7L? ~;;L$
sFilePath = value; {b=]JPE
} g' H!%<
8L6!CP_!
%R-"5?eTtu
public String getSFileName() W32bBzhL
{ 1[:?oEI
return sFileName; s?7g3H5#0k
} f9X*bEl9;`
yA \C3r'
a 0Hzf
public void setSFileName(String value) pRc@0^G
{ _{C:aIl[2
sFileName = value; WFsa8qv
} NuLQkf)
28>gAz.#
FF)F%o+:w
public int getNSplitter() aj|I[65
{ W6 f*>
return nSplitter; ?b:l.0m
} ,eF}`
PIsMx-i0
bL]*K$
public void setNSplitter(int nCount) qOqQt=ObU
{ w=e~ M
nSplitter = nCount; ZGH2
} 7rbl+:y2
} ^<.mUaP
?8)_,
o} YFDYi
/* |!aMj8i2
**Utility.java Jp=ur)Dj
*/ E,>/6AU
package NetFox; O*`] ]w]
XjuAVNY
[wj&.I{^s
public class Utility { 5BN!uUkm+
ggzg,~V
hwSn?bkw
public Utility() )apqL{u:=
{ Gp6|M2Vu_5
b(wW;C'#0p
9EIHcUXe
} ,mx>)}l95
)k.;.7dXe
//线程睡眠 b$l@Z&[]
public static void sleep(int nSecond) +DY%Y `0
{ %D)W~q-g
try{ nNSq6 Cj
Thread.sleep(nSecond); soRt<83
} _%?}e|epy
catch(Exception e) '+hiCX-_
{ qfd/t<?|D
e.printStackTrace (); Cb%?s
} oe=^CeW"
} 4. 7m*
ypSW9n
//日志 1(CpTaa
public static void log(String sMsg) vSb$gl5H
{ C4H M
System.err.println(sMsg); -R?~Yysd7K
} m-xSF]q=<
\tc4DS
Z@nWx]iz
public static void log(int sMsg) ODyK/Q3
{ Y6~/H
System.err.println(sMsg); s5_[[:c=^
} UA>UW!I
} Mj&q"G
j7IX"O%f\
(C dx7v2Nh
/* {*RyT.J
**TestMethod.java .]SE>3
*/ l}:&}
package NetFox; B[%FZm$`M
oKLL~X>!U
}1=V`N(
public class TestMethod { oJE~dY$Q
.bE+dA6:v
~Gx"gK0
public TestMethod() fjVGps$j
{ ///xx/weblogic60b2_win.exe 2R66 WKQ
try{ 2Z;wU]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _Q_"_*e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xE`uFHuS}
SiteFileFetch fileFetch = new SiteFileFetch(bean); u(iEuF;7
fileFetch.start(); +F=j1*'&
} `CP#S7W^
catch(Exception e){e.printStackTrace ();} 9%55R >s$
KAVe~j"
`irz'/"p
} }F=scbpXj
8h
L 1iA ^x
public static void main(String[] args) R>f$*T
{ $9k7A 8K
new TestMethod(); 1Tz5tU9kR
} p_pI=_:
} ?WyL|;b*
点击下载更多相关资料