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)); 'q, L*
} !B:wzb_
for(int i=0;i<nEndPos.length-1;i++) SeIL
{ ^_!2-QY.~
nEndPos = nStartPos[i+1]; H-5h-p k
} F|^tRL-
nEndPos[nEndPos.length-1] = nFileLength; }e0>Uk`[
} 66Bx,]"6
} h7cE"m
b2G1@f.U
y.+!+4Mg|
//启动子线程 Tv /?-`Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8Q\ T,C
for(int i=0;i<nStartPos.length;i++) Xn*>qm
{ 8Y&_X0T|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), se`^g ,]P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ql(~3/kA_
nStartPos,nEndPos,i); )bR`uV9<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [6cf$FS9
fileSplitterFetch.start(); )A=&3Ui)ab
} z-G*:DfgH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1CA%nqlng
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~xU\%@I\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p n(y4we
nEndPos = " + nFileLength); 4StoEgFS
// fileSplitterFetch[nPos.length-1].start(); ;$/]6@bqB
mWX{I2
qz&?zzz;
//等待子线程结束 u?lbC9}$
//int count = 0; hL}AgY@
//是否结束while循环 z\+Ug9Of
boolean breakWhile = false; (;cvLop
U]64HuL
%WAaoR&u
while(!bStop) H rI(uZ]
{ lCiRvh1K
write_nPos(); e(Y5OTus
Utility.sleep(500); a}5/?/
breakWhile = true; &"mWi-Mpl
~R C\
)bl^:C
for(int i=0;i<nStartPos.length;i++) "eZ~]m}L0
{ xY<*:&
if(!fileSplitterFetch.bDownOver) O2N~&<^
{ cs0rz= ZdH
breakWhile = false; \<Di|X1
break; p%ZAVd*|#V
} N.dcQQ_iS
} RLR\*dL1
if(breakWhile) !T RU
break; y[d>7fcf
:@K~>^+U
$_Q]3"U
//count++; a|kEza,]
//if(count>4) uQO\vRh0
// siteStop(); Q1[EiM3
} "`Y.5.
Y?xc#'
UIK4]cYC'
System.err.println("文件下载结束！"); iPdR;O'
} Z:.*fs5
catch(Exception e){e.printStackTrace ();} Bnh*;J0
} RKD$'UWX
mt}3/d
d~z%kl 5:
//获得文件长度 kadw1sYj
public long getFileSize() %z"n}|%!
{ -I.BQ
int nFileLength = -1; @H61^K<
try{ 7;$[s6$
URL url = new URL(siteInfoBean.getSSiteURL()); ~%QI#s?|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O[W/=j[
httpConnection.setRequestProperty("User-Agent","NetFox"); [BuAJ930#5
Yk=2ld;;
3h**y %^
int responseCode=httpConnection.getResponseCode(); KhZ\q|5
if(responseCode>=400) YWhp4`m
{ 'Oa(]Br[
processErrorCode(responseCode); UX@8
return -2; //-2 represent access is error FC#t}4as
} sPRo=LB
D),hSqJ"
tLzKM+Ct#
String sHeader; A0 $ds
}$@EpM
>8%O;3-m#
for(int i=1;;i++) |G(I,EPag
{ "J>8ZUP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); As>P(
//Utility.log(in.readLine()); Aga{EKd
sHeader=httpConnection.getHeaderFieldKey(i); h=ben&m
if(sHeader!=null) 9"f
{ gzEcdDD
if(sHeader.equals("Content-Length")) i^}ib RQbN
{ "Zu>cbE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ug8>|wCE
break; <Y+>a#T
} ~qkn1N%'
} /dwj:g0y
else >(C5&3^
break; v%;Nyab6$
} FZx.Yuv
} u+qj_Ej
catch(IOException e){e.printStackTrace ();} A9o"L.o)
catch(Exception e){e.printStackTrace ();} ub]"b[j\1
5v"Sv
2 sK\.yS
Utility.log(nFileLength); <8BNqbX
%:yVjb,Yf
Vu;z|L
return nFileLength; J7p?9
} Vw+RRi(
+k\cmDcb
}TRVCF1
//保存下载信息（文件指针位置） _bSn YhS
private void write_nPos() z9JZV`dNgz
{ |[X-i["y
try{ X1o=rT
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1ZO/R%[
output.writeInt(nStartPos.length); RuWu#tk
for(int i=0;i<nStartPos.length;i++) V-x/lo]Co
{ nTCwLnX(O
// output.writeLong(nPos); qL~|bfN
output.writeLong(fileSplitterFetch.nStartPos); ZG8Xr"
output.writeLong(fileSplitterFetch.nEndPos); &VTO9d
} Ue(\-b\)
output.close(); k;Ask#rs
} rT';7>{g
catch(IOException e){e.printStackTrace ();} {ZKXT8'
catch(Exception e){e.printStackTrace ();} l(d3N4iz
} Yz? 8n
FY"csZ
TV~S#yg+H
//读取保存的下载信息（文件指针位置） ;TulRx]EA
private void read_nPos() 0N):8`dY
{ v)<|@TD)
try{ tf6 Zz[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y=LN|vkQ
int nCount = input.readInt(); B~2M/&rM\
nStartPos = new long[nCount]; 'Xu3]'m*
nEndPos = new long[nCount]; j.+}Z |
for(int i=0;i<nStartPos.length;i++) S^A+Km3VB
{ 0ni/!}YP_
nStartPos = input.readLong(); G<Y}QhFU
nEndPos = input.readLong(); -YY@[5x?u
} {9-n3j}
input.close(); 0X}0,
} C=`MzZbJ
catch(IOException e){e.printStackTrace ();} JzmX~|=Xi
catch(Exception e){e.printStackTrace ();} ;&$f~P Q
} 3`Gb;D
gbziEjRe
=h|xlT
private void processErrorCode(int nErrorCode) jbp?6GW
{ 3ICMH
System.err.println("Error Code : " + nErrorCode); bVOJp% *s
} Zw_'u=r >
a([8r- zP
M=Y['wx
//停止文件下载 ?<1~KLPMhY
public void siteStop() Ww=b{lUD
{ <jG[ z69)
bStop = true; ["sm7yQ
for(int i=0;i<nStartPos.length;i++) \{;3'<
fileSplitterFetch.splitterStop(); Q-Oj%w4e
yZc#@R[0
z m+3aF
} Lmw4
} _ qU-@Y$
//负责部分文件的抓取 w+iIay
**FileSplitterFetch.java ^y[- e9O|
*/ bU$M)
package NetFox; gjn1ha"h%.
1t}
5IfC8drAs
import java.io.*; zoZ10?ojC
import java.net.*; /i(R~7;?
##nC@h@
m(IyW734I
public class FileSplitterFetch extends Thread { f0 kz:sZ9
QBb%$_Z
CTJwZY7
String sURL; //File URL *M'/z=V?%
long nStartPos; //File Snippet Start Position dP=,<H#]m
long nEndPos; //File Snippet End Position ;e$YM;;d
int nThreadID; //Thread's ID Yb4%W-5
boolean bDownOver = false; //Downing is over xB5QM #w\
boolean bStop = false; //Stop identical u,./,:O%=
FileAccessI fileAccessI = null; //File Access interface s&1}^'|
v\D.j4%ij
{\gpXVrn_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gjk;An
{ vsJM[$RF
this.sURL = sURL; p{AX"|QM"
this.nStartPos = nStart; ;*cCaB0u
this.nEndPos = nEnd; FT\%=>{
nThreadID = id; "6gBbm
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p\DSFB
} 4@QR2K|
<[?ZpG
Rd[^)q4d$w
public void run() Y(=A HmR
{ f<M!L>+M6
while(nStartPos < nEndPos && !bStop) r9n:[A&HE
{ -Eoq#ULvR
* 'Bu-1{
K9ek
try{ q^h/64F
URL url = new URL(sURL); 7G%:ckg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [DvQk?,t
httpConnection.setRequestProperty("User-Agent","NetFox"); o8~<t]Ejw
String sProperty = "bytes="+nStartPos+"-"; $E}N`B7
httpConnection.setRequestProperty("RANGE",sProperty); \LM.>vJ
Utility.log(sProperty); >L433qR
~.CmiG.7
k|^`0~E
InputStream input = httpConnection.getInputStream(); 5]K2to)>`
//logResponseHead(httpConnection); !\!j?z=O8
hGRHuJ
q4Mv2SPT
byte[] b = new byte[1024]; d<[L^s9
int nRead; f$qkb$?]}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }6gum
{ I.it4~]H
nStartPos += fileAccessI.write(b,0,nRead); %Z*N /nU
//if(nThreadID == 1) w<Bw2c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 73JrK_h
} b4Pa5w
85lcd4&~
biENRJQ.
Utility.log("Thread " + nThreadID + " is over!"); =yWdtBng
bDownOver = true; SGu`vN]
//nPos = fileAccessI.write (b,0,nRead); Z>pZ|
} nO#x"
catch(Exception e){e.printStackTrace ();} ?C']R(fQ\
} +[}<u--
} k; >Vh'=X
D4sp+
<6+T&Ov6
//打印回应的头信息 7"1]5\p^g
public void logResponseHead(HttpURLConnection con) `1uGU[{x
{ HlEHk'
for(int i=1;;i++) C7K]c4T
{ ""*g\
String header=con.getHeaderFieldKey(i); ,c&gw tdl
if(header!=null) ^I)+u>fJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^0-e.@
Utility.log(header+" : "+con.getHeaderField(header)); {W HK|l
else dWdD^>8Ef
break; r1 b"ta
} 45&Rl,2
} MaPI<kYQv
d.HcO^
';v1AX}5q
public void splitterStop() }}Z2@}
{ ]^,!;do
bStop = true; "C?H:8W
} @9R78Zra
)S;3WnQ)
'V&Tlw|
} /fdrf
'_5|9 }
RT${7=
/* ~/XDA:nfL:
**FileAccess.java XlnSh<e
*//文件访问(定位，写) P#D|CP/Cu
package NetFox; v7\rW{~Jd&
import java.io.*; wD4[UU?
}F"98s W
>GLoeCRNu
public class FileAccessI implements Serializable{ xsiJI1/68
Z{gm4YV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cL][sI
RandomAccessFile oSavedFile; ".2d{B
long nPos; *f_A:`:
7iyx_gyo
%k~ezn
public FileAccessI() throws IOException Dt{WRe\#
{ (L yKo
this("",0); $x,EPRNs
} =3`|D0E
]k'^yc{5
gA% A})
public FileAccessI(String sName,long nPos) throws IOException \BN$WV
{ { {:Fs
oSavedFile = new RandomAccessFile(sName,"rw"); C|h Uyo
this.nPos = nPos; w*&vH/D
oSavedFile.seek(nPos); Y B,c=Wx
} kW1w;}n$
zWH)\>X59
x,zYNNx5g
public synchronized int write(byte[] b,int nStart,int nLen) @b,6W wc
{ 7?{y&sf
int n = -1; @$'pMg
try{ TiF+rA{t
oSavedFile.write(b,nStart,nLen); 3+(lKd
n = nLen; #<Lv&-U<KT
} -*i_8`
catch(IOException e) u0A$}r$L
{ 53gLz_ee
e.printStackTrace (); .FC+
} ifu!6_b.
/sj*@HF=
,aa 4Kh
return n; ?~4x/d%
} W)J MV
?c+$9
3W]gn8
} f*xr0l
:0QDV~bs
T\g+w\N
/* CWocb=E
**SiteInfoBean.java 3u&,3:
*/ GC'e
package NetFox; ir"t@"Y;o
=5Nh}o(l?
O ;[Mi
public class SiteInfoBean { GM?s8yZ<
aKWxLe
^g5E&0a`g
private String sSiteURL; //Site's URL k!}(a0h
private String sFilePath; //Saved File's Path 8A.7q
private String sFileName; //Saved File's Name EmR82^_:
private int nSplitter; //Count of Splited Downloading File d~QM@<SV
w;j<$<4=7
MkL2I+*
public SiteInfoBean() _> x}MW+
{//nSplitter的缺省值为5 0y+^{@lU
//default value of nSplitter is 5 @!u{>!~0
this("","","",5); d9BFeq8
} sZT~5c8
^D6TeH
goA=U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) elQjPvb
{ Z\xnPhV
sSiteURL= sURL; *OznZIn
sFilePath = sPath; BAY e:0
sFileName = sName; 0 !{X8>x
this.nSplitter = nSpiltter; ydo9 P5E
rq4g~e!S
_#NibW
} iC/*d
6lv@4R^u
u}|v;:|j
public String getSSiteURL() #v<`|_
{ -Dx3*ZhP
return sSiteURL; Yj/o17
} 6]~/`6Dub
\Ta5c31S+
PJ0~ymE1~G
public void setSSiteURL(String value) ]%HxzJ
{ FHw%ynC
sSiteURL = value; Mms|jFoQ
} vxTn
_:=\h5}8
HbI{Xf[6LP
public String getSFilePath() ,;Wm>V)o
{ `bfUP s
return sFilePath; wjwCs`
} U4fv$gV
!p!Qg1O6o
't&1y6Uu
public void setSFilePath(String value) \t&! &R#
{ TB* t^E
sFilePath = value; G}g;<,g~
} 6XF Ufi+
UMe?nAC
sTl^j gV7j
public String getSFileName() t;6<k7h
{ "aF2:E'
return sFileName; F |BY]{
} v_EgY2l(
~`FRU/@r
g9|OhymB
public void setSFileName(String value) cZ|*Zpk
{ RQ=$, i`
sFileName = value; zKGZg>q
} yuBRYy#E|%
el*|@#k}
$<nRW*d
public int getNSplitter() oo\^}jb
{ S',h*e
return nSplitter; BInSS*L
} |ugdl|f
h~\k;ca
gfj_]
public void setNSplitter(int nCount) iL);bv W
{ 1>rQ).eT
nSplitter = nCount; !DFTg4xb
} P"^Yx8L#
} Gg9s.]W
P|@[D=y
}6\,kFc
/* ?V8Fgd
**Utility.java XXum2eA
*/ -Yse^(^"s
package NetFox; mc%. 8i
nUpj+F#
Q4-d|
public class Utility { 7FcZxu\
(0q`eO2
z2YYxJc&w
public Utility() 9DhM 9VU
{ ygnZ9ikh<-
hRX9Du`$
0.x+ H9z
} e8("G[P>
#X'-/q`.
//线程睡眠 @[9
public static void sleep(int nSecond) 'RKpMdoz
{ ,]wQ]fpt
try{ lwX9:[Z
Thread.sleep(nSecond); Kt*fQ `9
} / ^d9At614
catch(Exception e) ^6kl4:{idE
{ <M1*gz
e.printStackTrace (); _lkVT']
} 1a(\F7
} 2~f*o^%l
KPO w
//日志 /kG?I_z
public static void log(String sMsg) -c?x5/@3
{ N.q~\sF^
System.err.println(sMsg); #)7`}7N
} =@M9S
z3i`O La
Yv]vl6<
public static void log(int sMsg) VVch%
{ BedL `[,
System.err.println(sMsg); 51|s2+GG
} "rLm)$I
} siCi+Y
*uRDB9#9,
##Pzc~xSn
/* jy.L/s
**TestMethod.java 'XKfKv >;
*/ WuY#Kx~2
package NetFox; U.SC,;N^
m}?jU
[>?|wQy>=
public class TestMethod { ];Noe9o
faRQj:R8
?GNRab
public TestMethod() 9)vU/fJ|
{ ///xx/weblogic60b2_win.exe 6/L[`n"G
try{ _VdJFjY?zc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n$SL"iezW?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bS8$[7OhX
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7=fNvES2
fileFetch.start(); (Ud"+a
} 9?ll(5E
catch(Exception e){e.printStackTrace ();} A]0R?N9wb_
n^;-&
{ObY1Y`ea
} }rmr0Bh
Dz~^AuD6
k8stXW-w
public static void main(String[] args) hk5!$#^
{ >ph=?MKD
new TestMethod(); E]~#EFc
} z.hq2v
} - i2^ eZl
点击下载更多相关资料