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)); ZpBP#Y*
} ij3W8i9'
for(int i=0;i<nEndPos.length-1;i++) W 9}xfy09
{ P&:[pPG
nEndPos = nStartPos[i+1]; TOa6sB!H
} p__N6a
nEndPos[nEndPos.length-1] = nFileLength; p_JWklg^
} XUUP#<,s
} AkO);4A;Jd
'<ZHzDW@
]Z=al`-
//启动子线程 -lv(@7o~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~>0H k}Hv
for(int i=0;i<nStartPos.length;i++) V=1zk-XC
{ w"QZ7EyJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tgl 4pAc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q j9q
nStartPos,nEndPos,i); 0fUsERr1*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uT<<G)v)
fileSplitterFetch.start(); w?N>3`Jnf
} C#)T$wl[E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <1*\ ~CX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kG}F/GN?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2@ZRz%(Oa&
nEndPos = " + nFileLength); gnxD'1_
// fileSplitterFetch[nPos.length-1].start(); ?(Plb&kR
WT1y7+_g(d
!V/7q'&t=
//等待子线程结束 anfnqa8
//int count = 0; [>3dhj[;
//是否结束while循环 ,Sy&?t}`
boolean breakWhile = false; mU]^PC2[
{&B0kjf
cc}#-HKR[
while(!bStop) V+l7W
{ mV4gw'.;7
write_nPos(); YH^@8
Utility.sleep(500); Y(?SE< 4R
breakWhile = true; \l 8_aj
M_r[wYt!
zx.SRs$
for(int i=0;i<nStartPos.length;i++) /nX_Q?mo
{ r{SDJa
if(!fileSplitterFetch.bDownOver) nvNF~)mu
{ 8]1,EE<
breakWhile = false; )"6"g9A
break; EdSUBoWF}
} 5tLb o
} MLmaA3
if(breakWhile) DVKb`KJ"
break; u$(ei2f
Q|S>C%4?
#)[.Xz:U
//count++; "*W# z
//if(count>4) T34Z#PFwe
// siteStop(); 5IFzbL#q#f
} @v&s|X'
X-TGrdoX
&%qDi_UD
System.err.println("文件下载结束！"); .c__T{<)[
} KU+\fwYpnk
catch(Exception e){e.printStackTrace ();} ]IeLKcn
} 8Djki]
4*5e0:O
3?L[ohKH?:
//获得文件长度 LEOa=(mN\
public long getFileSize() nLv~)IQ}:
{ u%I%4 gM
int nFileLength = -1; 2efdJ&eIV
try{ s@y;b0$gk
URL url = new URL(siteInfoBean.getSSiteURL()); Hz==,NR-W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6iF&!Fd>J
httpConnection.setRequestProperty("User-Agent","NetFox"); -p>1:M <
I;eoy,
7l~^KsX
int responseCode=httpConnection.getResponseCode(); !y'>sAf
if(responseCode>=400) t*A[v
{ H270)Cwn+
processErrorCode(responseCode); J2! Q09 }5
return -2; //-2 represent access is error J]{<Z?%
} bX(/2_l
p4UEhT
hN]l $Ct
String sHeader; [?O4l`
)|k#cT{=M
_<Ij)#Rq7
for(int i=1;;i++) I.T?A9Z
{ dGkw%3[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $?]`2*i
//Utility.log(in.readLine()); 4dLnX3 v
sHeader=httpConnection.getHeaderFieldKey(i); Rt&5s)O'
if(sHeader!=null) ?_A[E]/H
{ ,r]H+vWS
if(sHeader.equals("Content-Length")) 3(,m(+J[S
{ .>.GQUr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '<uM\v^k
break; bj6Yz,g F
} M"/Jn[
} X"r.*fb;N
else RjPkH$u'Pj
break; o$+R
} r `n|fD.
} Nq8 3 6HL
catch(IOException e){e.printStackTrace ();} 7Hgn/b[?b
catch(Exception e){e.printStackTrace ();} >wt.)c?5
1IS1P)4_0
xU0iz{9
Utility.log(nFileLength); Fw{@RQf8
wCR! bZ w
=N{?ll6x7g
return nFileLength; H@$K/
} k}&wy
^v cnDi
]Sa#g&}T>
//保存下载信息（文件指针位置） /HhA2 (g%
private void write_nPos() YI"!&a'yj
{ A%F8w'8(
try{ R%\3[
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]BbV\#
output.writeInt(nStartPos.length); HJ]e%og
for(int i=0;i<nStartPos.length;i++) jdu6P+_8n
{ |9]-_a
// output.writeLong(nPos); e@0|fB%2
output.writeLong(fileSplitterFetch.nStartPos); eF.nNu
output.writeLong(fileSplitterFetch.nEndPos); oST)E5X;7
} W,Q>3y*
output.close(); 'h'pM#D
} rA B=H*|6
catch(IOException e){e.printStackTrace ();} Y<VX.S2kf
catch(Exception e){e.printStackTrace ();} xW5`.^5
} 'l~7u({u
Oy=0Hsh@x
_BJ:GDz>
//读取保存的下载信息（文件指针位置） ]w;t0Bk
private void read_nPos() P![ZO6`:W'
{ 0[%{YmI{W
try{ n/Fxjf0W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mHju$d
int nCount = input.readInt(); {S9gOg
nStartPos = new long[nCount]; =5B5
nEndPos = new long[nCount]; $fD%18
for(int i=0;i<nStartPos.length;i++) qg`ae
{ Sq_.RU
nStartPos = input.readLong(); z8}QXXa
nEndPos = input.readLong(); a]V8F&)g#
} 1 Vt,5o5
input.close(); V )oXJL
} pqpsa'
catch(IOException e){e.printStackTrace ();} ri59LYy=
catch(Exception e){e.printStackTrace ();} '*rS,y
} [u K,.G
]oSx]R>{f
HP[B%
private void processErrorCode(int nErrorCode) NdLe|L?c
{ cRr3!<EZ
System.err.println("Error Code : " + nErrorCode); K3 BWj33
} "'Fvt-<^S7
1z&"V}y
|&WYu,QQ4
//停止文件下载 YB7A5
public void siteStop() C}xfo}i
{ #'%ii,;wQ
bStop = true; NwYQ6VEA
for(int i=0;i<nStartPos.length;i++) t/O^7)%
fileSplitterFetch.splitterStop(); We}9'X}
leNX5 sX
,=Wj*S)~
} F3!@|/<w
} t6KKfb
//负责部分文件的抓取 DKMkCPX%
**FileSplitterFetch.java =#9#unvE!
*/ PZV>A!7C8n
package NetFox; CStNCBZ|\
YiuV\al
'G % ]/'_U
import java.io.*; LXby(|<j
import java.net.*; <#M1I!R
k CGb~+
<BBzv-?D
public class FileSplitterFetch extends Thread { 420K6[
iCiKr aW
jA:'P~`Hj
String sURL; //File URL MH'%E^n `
long nStartPos; //File Snippet Start Position `&fW<5-
long nEndPos; //File Snippet End Position LNk :PD0m
int nThreadID; //Thread's ID `fEzE\\!*
boolean bDownOver = false; //Downing is over bV(BwWm
boolean bStop = false; //Stop identical cOpe6H6,bz
FileAccessI fileAccessI = null; //File Access interface Z P|k3
mk~CE
A ?V-Sz#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wY\,b*x
{ -;"A\2_y
this.sURL = sURL; $0$sDN6)x
this.nStartPos = nStart; sXPva@8_
this.nEndPos = nEnd; DcaKGjp
nThreadID = id; ynMYf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~e[qh+
} AtHkz|sl
=eW4?9Uq
4|\M`T
public void run() .c<U5/
{ 8irTGA
while(nStartPos < nEndPos && !bStop) F)eP55C6
{ (HeSL),1
A~>B?Wijqg
zpf<!x^
try{ 5GJkvZtFY
URL url = new URL(sURL); =(TMcu$4`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n>Oze7hVY
httpConnection.setRequestProperty("User-Agent","NetFox"); yG~Vvpv
String sProperty = "bytes="+nStartPos+"-"; 67T.qX2I$
httpConnection.setRequestProperty("RANGE",sProperty); e&ZTRgYdi
Utility.log(sProperty); RJDk7{(
INk|NEX
|)jR|8MAE
InputStream input = httpConnection.getInputStream(); #H~$^L
//logResponseHead(httpConnection); UjJ&P)
751Qi
6_yatq5c
byte[] b = new byte[1024]; Kt]vTn7!9
int nRead; G;/> N'#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Imzh`SI,
{ +B+cN[d
nStartPos += fileAccessI.write(b,0,nRead); *&_A4)
//if(nThreadID == 1) @*6_Rp"@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dW5r]D[Cx
} zU0JwZi
IJPyCi)
$'!n4}$}
Utility.log("Thread " + nThreadID + " is over!"); 2|RxowXZ"
bDownOver = true; WyQ8}]1b
//nPos = fileAccessI.write (b,0,nRead); lQ[JA[
} TOP,]N/F H
catch(Exception e){e.printStackTrace ();} qnd] UUA^
} @#o7U
} 8QKu
91a);d
j[$+DCO#|m
//打印回应的头信息 Zcc7 7dRA
public void logResponseHead(HttpURLConnection con) T# tFzbr
{ I(j{D>v
for(int i=1;;i++) 9/&1lFKJ
{ =:xJZy$
String header=con.getHeaderFieldKey(i); 8)`
if(header!=null) BTA2['
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JiA1yt
Utility.log(header+" : "+con.getHeaderField(header)); Mj19;nc0I
else l`j@QP
break; iztF
} QqeF
} lY[1P|]
9]{Ss$W3x
3],(oQq^
public void splitterStop() 0q1+5
{ <P Vmr2Jp"
bStop = true; hSh^A5 /
} >Ij#+=
H3JDA^5
t3Iij0b~
} AMK3I`=8WO
0R&7vn
,~K4+ t_
/* un,W{*s8*
**FileAccess.java AZJ|.mV q
*//文件访问(定位，写) MAc/ T.[
package NetFox; `E>o:tff
import java.io.*; T?-K}PUcQ
% <%r
VOmS>'$
public class FileAccessI implements Serializable{ `-rtU
=D 5!Xq'|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I=K<%.
RandomAccessFile oSavedFile; Zl2doXC
long nPos; D6FG$SV
#Pq6q.UB
*b1NVN$
public FileAccessI() throws IOException &#]||T-
{ 0@#d($'1?Z
this("",0); Ti5"a<R4m6
} f%STkL)
)q%DRLD'G
*>j4tA{b@v
public FileAccessI(String sName,long nPos) throws IOException a'\fS7aE0l
{ sQY0Xys<4
oSavedFile = new RandomAccessFile(sName,"rw"); JG'&anbm
this.nPos = nPos; jATN):8W
oSavedFile.seek(nPos); PF;`mdi-,
} \88IFE
5kj=Y]9\I
}/.b@`Dh;
public synchronized int write(byte[] b,int nStart,int nLen) p:|p?
{ }j#c#''i
int n = -1; d[KG0E5`
try{ mz .uK2l{
oSavedFile.write(b,nStart,nLen); `"E<%$|ZQy
n = nLen; g*:f#u5
} !iGZo2LV
catch(IOException e) 6q^.Pg-Y
{ S 5nri(m
e.printStackTrace (); *s"{JrG`O
} locf6%2g~
pd}af iF
@X0$X+]E*8
return n; '[Ch8Yf\
} 6rzXM`cs
I=yy I
;(9q, )
} vC!}%sxVw_
C+c;UzbD
`Jon^&^;|
/* 9.$k^|~
**SiteInfoBean.java I)X33X,
*/ |<1
package NetFox; 9mH/xP:y
"EC,#$e%ev
PaYsn *{})
public class SiteInfoBean { 4o*wLCo7^
gS4@3BOw&.
YXhxzH hPd
private String sSiteURL; //Site's URL `G^MTDp?L+
private String sFilePath; //Saved File's Path ;?0k>
private String sFileName; //Saved File's Name |\/Y<_)JD
private int nSplitter; //Count of Splited Downloading File Qf}b3WEAI
:Sd iG=t
G4eY}3F7,4
public SiteInfoBean() Mk@%Wuxg2
{//nSplitter的缺省值为5 D^9r#&
//default value of nSplitter is 5 F%pYnHr<
this("","","",5); DkGC+Dw
} v-mhqhb
d@-bt s&3
Fm3B8Int
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?4,e?S6,[
{ 48 `k"Uy
sSiteURL= sURL; <Sx-Ca7
sFilePath = sPath; Jx8?x#}
sFileName = sName; I+]q;dF;
this.nSplitter = nSpiltter; Cj x(Z]
&k4)&LQJ
+5:oW~ ;
} !yQ#E2/A
0"_FQv
Eh&et0&=g
public String getSSiteURL() nT.2HQ((Xg
{ HG/`5$L +}
return sSiteURL; !!4` #Z0+#
} W7QcDR y6
7C%z0/
^%V^\DK
public void setSSiteURL(String value) <g|\]\C|
{ l|c#
sSiteURL = value; B~oc.sg
} O%.c%)4Xo
@3hA\3ot^
;LM,<QJ
public String getSFilePath() R7)2@;i
{ h`0'27\C
return sFilePath; hqA6%Y^k
} `is."]%f
V9tG2mLf>
'<.@a"DnJ
public void setSFilePath(String value) Qb}1tn)
{ B=mk@gX,G
sFilePath = value; %4/>7 aB]Y
} #G;0yB:76
',o ,o%n
yaiw|j`A
public String getSFileName() Ydw04WEJ
{ Dl2`b">u
return sFileName; Uk=-A @q
} lj{Jw.t
XANPI|
df=G}M(
public void setSFileName(String value) mT@8(
{ dy^Zlu` f
sFileName = value; '+6SkZ
} 6tC0F=
ai!zb2j!E
{=5Wi|
public int getNSplitter() qHT_,\l2
{ Flrpk`4
return nSplitter; L1FTh
} h JVy-]
5E|y5|8fb
i/j DwA
public void setNSplitter(int nCount) nU{}R"|
{ uAd4Zz
nSplitter = nCount; \t6k(5J
} EZ6\pyNB0#
} 8<gYB$* S
gVM&wo |
'P1I-ue
/* j06q3N"
**Utility.java Qy>n]->%
*/ $e bx
package NetFox; eI%{/>
D"x;/I
>5rb4
public class Utility { s4RqY*VK
6Qo YX] .
?<YQ %qaW7
public Utility() JDTlzu1hR
{ R^DZ@[\iV
UcZ20inj0
gj(|#n5C
} p$mx
- '<K_e;
//线程睡眠 v}vwk8
public static void sleep(int nSecond) p_^Jr*Mv
{ 8`QbUQ6
try{ g4Y1*`}2f
Thread.sleep(nSecond); P2U^%_~
} q5@N//<DNN
catch(Exception e) X+0+}S
{ 2P`Z>_
e.printStackTrace (); FTVV+9.l:
} [;?CO<
} Zb p+b;
,;&j*qFi
//日志 M>eMDCB\
public static void log(String sMsg) Wu}84W"!.V
{ XLu Y
System.err.println(sMsg); 25NTtj:X
} =tkO^
M<nKk#!+h
O,a1?_m8
public static void log(int sMsg) fJiY~mQ
{ v(|Arm?
System.err.println(sMsg); 2LO8SJ#
} %<^IAMkp
} +4*3aWf`
(_9u<
`RF0%Vm~t
/* {5GXN!f
**TestMethod.java C\3;o]
*/ 9;ZaL7>
package NetFox; 0~/'c0Ho
nzcXL =^r3
qKSS 2f $
public class TestMethod { (dH "b *
eYpK!9
o_i N(K
public TestMethod() _~QiQDq
{ ///xx/weblogic60b2_win.exe R^hlfKnt
try{ rf ?\s/#OY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^MXW,xqb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sB~|V <
SiteFileFetch fileFetch = new SiteFileFetch(bean); q6]T;)U&
fileFetch.start(); d-rqZn}
} ;h7W(NO~z
catch(Exception e){e.printStackTrace ();} 99KW("C1F
+u[^@>_I0
OsrHA
} x\i+MVR-
>WcOY7
B-1Kfc
public static void main(String[] args) : Yb_
{ BzXTHFMSy
new TestMethod(); p0|PVn.^h
} kgv29j?k;
} Qq|c%FZ
点击下载更多相关资料