http断点续传简单实现（java)

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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)); FJ-X~^
} ./5LV)_`
for(int i=0;i<nEndPos.length-1;i++) hNU$a?eVpR
{ -J &y]'
nEndPos = nStartPos[i+1]; Z:eB9R#2y
} gi {rqM
nEndPos[nEndPos.length-1] = nFileLength; k4T`{s}e
} KEfN!6
} Uzh#zeZ`<
Z;/QB6|%
qh9d.Q+n
//启动子线程 O1+OE!w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QrBb!.r
for(int i=0;i<nStartPos.length;i++) L;RHshTy
{ !%X~`&9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nIZ;N!r=i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), da'1H
nStartPos,nEndPos,i); hufpky[&8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ICdfak
fileSplitterFetch.start(); aFw \w>*^
} kB[l6`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O,.c gX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'Nkd *
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -XASS%
nEndPos = " + nFileLength); Dc@OrQu
// fileSplitterFetch[nPos.length-1].start(); l6_dVK;s
t]gZ^5
L`3;9rO
//等待子线程结束 !(gMr1}w
//int count = 0; NJ^Bv`
//是否结束while循环 _w}l,
boolean breakWhile = false; k%D|17I
gUr#3#
Uc%kyTBm1
while(!bStop) #nq$^H
{ M"\Iw'5$
write_nPos(); {"PIS&]tR
Utility.sleep(500); z!s1$5:"0
breakWhile = true; ~n=oPm$pR
t1`.M$
1S+lHG92I
for(int i=0;i<nStartPos.length;i++) 3-/F]}0y6
{ H|)F-aL[
if(!fileSplitterFetch.bDownOver) \X2r?
{ icK>|
breakWhile = false; Uee(1
break; S:lie*Aux*
} eC{St0
} gWD46+A){
if(breakWhile) AXpg_JC
break; <EKTFHJ!
U3**x5F_
N&yr?b'!-*
//count++; m)l'i!Y
//if(count>4) z[Ah9tM%
// siteStop(); 8-B6D~i
} =f?vpKq40
*qZBq&7tb
i&TWIl8
System.err.println("文件下载结束！"); cY^'Cj
} #=V\WQb
catch(Exception e){e.printStackTrace ();} :u]QEZ@@
} gb{8SG5ac
:\Q#W4~p
T@jv0/(+
//获得文件长度 6bDizS}
public long getFileSize() ~_SRcM{
{ i@`qam
int nFileLength = -1; V]Rt[l]
try{ |b4f3n
URL url = new URL(siteInfoBean.getSSiteURL()); 0Ke2%+yqJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +!Q*ie+q
httpConnection.setRequestProperty("User-Agent","NetFox"); _v[gJ(F
u!-v1O^[
4L bll%[9
int responseCode=httpConnection.getResponseCode(); [*J?TNk
if(responseCode>=400) :85QwN]\
{ WF_v>g:g
processErrorCode(responseCode); gNJdP!(t
return -2; //-2 represent access is error 11vAx9
} EQtYb"_
y?V^S;}&]
oj/#wF+
String sHeader; %Yt;)q3U
K&VMhMVb
<0!<T+JQ
for(int i=1;;i++) ;i?rd f
{ WjBH2v
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :K~sazs7J
//Utility.log(in.readLine()); |It&1fz}
sHeader=httpConnection.getHeaderFieldKey(i); Cg(&WJw(ep
if(sHeader!=null) sd%m{P2
{ Bg[_MDWc-P
if(sHeader.equals("Content-Length")) xO^lE@a o
{ }_BNi;H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wo(m:q(Om
break; Eunmc
} 3a|pk4M
} h1H$3TpP
else QHxof7
break; H$V`,=H
} \.'[!GE*c
} 1Va=.#<
catch(IOException e){e.printStackTrace ();} F9"Xu-g
catch(Exception e){e.printStackTrace ();} b<%c ]z
Wecxx^vtv6
Vr@tSc&
Utility.log(nFileLength); R^mkQb>m.
|c>.xt~
c^rWS&)P
return nFileLength; 6RG63+G
} ,^7]F"5
on;>iKta9
FJ{/EloF
//保存下载信息（文件指针位置） W] WH4.y
private void write_nPos() gA`QV''/:
{ "Zy:q'`o
try{ jK".iqx2L
output = new DataOutputStream(new FileOutputStream(tmpFile)); zwU1(?]I{
output.writeInt(nStartPos.length); t,n2N13
for(int i=0;i<nStartPos.length;i++) +/bD9x1H
{ s(?%A
// output.writeLong(nPos); (d/!M n6L
output.writeLong(fileSplitterFetch.nStartPos); +v~x_E5FP
output.writeLong(fileSplitterFetch.nEndPos); \H9:%Tlp~4
} d}%-vm} 0
output.close(); ftKL#9,s(
} ;%Px~g
catch(IOException e){e.printStackTrace ();} NG`Y{QT6N
catch(Exception e){e.printStackTrace ();} =XtQ\$Pax
} ^ir)z@P?V
O c.fvP^ZD
O._\l?m
//读取保存的下载信息（文件指针位置） R58NTPm
private void read_nPos() F2\&rC4v
{ 9|3sNFGX
try{ /OYa1,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E%(s=YhW
int nCount = input.readInt(); OwEu S#-
nStartPos = new long[nCount]; <5^m`F5
nEndPos = new long[nCount]; PD^G$LT
for(int i=0;i<nStartPos.length;i++) r \[|'hA
{ I:HrBhI)wP
nStartPos = input.readLong(); |Y8}*C\M.h
nEndPos = input.readLong(); 1szObhN-l
} 4l{$dtKbI
input.close(); 93Zij<bH?e
} Mna yiJl
catch(IOException e){e.printStackTrace ();} c%WO#}r|
catch(Exception e){e.printStackTrace ();} <W>A }}q
} ~ g-(
g*(z.
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private void processErrorCode(int nErrorCode) &2U%/JqY
{ WzoI0E`
System.err.println("Error Code : " + nErrorCode); Faa>bc~E
} {6WG
s7HKgj
^{{a v?h
//停止文件下载 q)f_!N
public void siteStop() 0}"\3EdAbD
{ E .28G2&
bStop = true; [& Z- *a
for(int i=0;i<nStartPos.length;i++) 1r};cY6
fileSplitterFetch.splitterStop(); KK5;6b
-8Hc M\b
5eE\ X /
} o2=):2x r{
} Y9|!=T%
//负责部分文件的抓取 d:w/{m%#
**FileSplitterFetch.java wJ pb$;
*/ /a<UKh:A[
package NetFox; U<Tv<7`
7y&6q`y E
Jfk#E^1
import java.io.*; NJ+$3n om
import java.net.*; FZO&r60$E
iCA-X\E
N$=9R
public class FileSplitterFetch extends Thread { c|JQ0] K
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k*n~&y:O
String sURL; //File URL .d}yQ#5z
long nStartPos; //File Snippet Start Position Lui6;NY
long nEndPos; //File Snippet End Position Q(cLi:)X2
int nThreadID; //Thread's ID e@ D}/1~=
boolean bDownOver = false; //Downing is over rAAx]nQ@
boolean bStop = false; //Stop identical >Oj$Dn=
FileAccessI fileAccessI = null; //File Access interface ;l~a|KW0
l^}u S|c(
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (oR~%2K
{ xZ)K#\
this.sURL = sURL; l`N4P
this.nStartPos = nStart; )DhE~
this.nEndPos = nEnd; iN. GC^l
nThreadID = id; 5I,NvHD4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~?Vod|>
} E0Q6Ryn
auc:|?H~1n
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public void run() &Z[+V)6,,
{ Pj]^p{>
while(nStartPos < nEndPos && !bStop) ZzNHEV
{ M9A1 8d|
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$u.rO7)
try{ (*P`
URL url = new URL(sURL); ;akW i]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B*mZxY1
httpConnection.setRequestProperty("User-Agent","NetFox"); .:f ao'
String sProperty = "bytes="+nStartPos+"-"; g%"SAeG<K
httpConnection.setRequestProperty("RANGE",sProperty); l[IL~
Utility.log(sProperty); |n)4APX\Q
:d9GkC
T)sIV5bk
InputStream input = httpConnection.getInputStream(); k kAg17 ^
//logResponseHead(httpConnection); {q`8+$Z;
>n3GvZ5%
] 1pIIX}
byte[] b = new byte[1024]; p<H_]|7$7U
int nRead; 1t^y?<)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x}pH'S7
{ "i(f+N,)
nStartPos += fileAccessI.write(b,0,nRead); \t1#5
//if(nThreadID == 1) 'DVn /3?X
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K=o {
} XJPIAN~l
o]4BST(A
.pWRV<25
Utility.log("Thread " + nThreadID + " is over!"); s7sd(f]=
bDownOver = true; &hkD"GGe
//nPos = fileAccessI.write (b,0,nRead); 3'kKbrk [
} 7Z`4Kdh .
catch(Exception e){e.printStackTrace ();} T@.+bD
} G gA:;f46
} X!LiekU!D
9ybR+dGm+
Z(c SM
//打印回应的头信息 ;Us6:}s
public void logResponseHead(HttpURLConnection con) SQ> Yf\
{ Bo8f52|
for(int i=1;;i++) Z(tJd,
{ :*,!gf
String header=con.getHeaderFieldKey(i); D((/fT)eD
if(header!=null) )s^gT]"N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fqbeO9x
Utility.log(header+" : "+con.getHeaderField(header)); 9)]`le
else eA(\#+)X `
break; Ncbe{}<md
} O0z-jZ,])
} h ChO
]}].Aq
@xBb|/I
public void splitterStop() #&IrCq+
{ QxE%C
bStop = true; ty~Sf-Pri
} d!:/n
w^&UMX}
g]HxPq+O
} ]kmAN65c
/<LjD
p gLhxc:
/* N?{Zrff2"O
**FileAccess.java y'8T=PqY[t
*//文件访问(定位，写) \G v\&_
package NetFox; -u%o);B
import java.io.*; nt|n[-}
Q+K]:c
*8a[M{-X
public class FileAccessI implements Serializable{ /_cpSq
UdkNb}L
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p%>!1_'(
RandomAccessFile oSavedFile; ~l'[P=R+8
long nPos; / zNVJhC
:/=P6b;
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public FileAccessI() throws IOException w/o8R3F
{ 9m>L\&\_e
this("",0); Th%w-19,8
} lmoYQFkYP
&f'Lll
hOLlZP+
public FileAccessI(String sName,long nPos) throws IOException l>`S<rGe
{ 8b,Z)"(U3
oSavedFile = new RandomAccessFile(sName,"rw"); #Qz9{1\G
this.nPos = nPos; K ~\b+
oSavedFile.seek(nPos); qfFa" a
} LL3| U
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~8k`~t!
public synchronized int write(byte[] b,int nStart,int nLen) gPKO-Fsd"
{ |Zn,|-iW
int n = -1; S?v;+3TG
try{ \J(~ Nv5!
oSavedFile.write(b,nStart,nLen); X J]+F
n = nLen; 2i6P<&@
} ^v;8 (eF
catch(IOException e) Gv)*[7
{ f~=e
e.printStackTrace (); }o GMF~
} "0G)S'
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return n; O&.gc p!
} uKIR$n"
iN u k5
<4?(|Vh[m]
} ;erxB6*
!&KE">3Qu
65&+Fv
/* }VH`\g}
**SiteInfoBean.java z9AX8k(B6
*/ E0r#xmk
package NetFox; :]\-GJV5
* e,8o2C$
M#],#o*G
public class SiteInfoBean { 9J49s1
6 ;\>,
y>UQm|o<W
private String sSiteURL; //Site's URL /WAOpf5
private String sFilePath; //Saved File's Path `a7b,d
private String sFileName; //Saved File's Name K^AIqL8
private int nSplitter; //Count of Splited Downloading File <3k9 y^0
\@6w;tyi
B$97"$#u
public SiteInfoBean() i"!j:YEo
{//nSplitter的缺省值为5 LGRhCOP:
//default value of nSplitter is 5 G @L`[Wu
this("","","",5); r`0oI66B/
} ![%:X)?
14-uy.0[
@DR?^ qp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) It'PWqZtG
{ Q?m= a0g
sSiteURL= sURL; y7R{6W_U>
sFilePath = sPath; ?y*yl
sFileName = sName; Z +}# Ic
this.nSplitter = nSpiltter; Y#-pK)EeU
U3>ES"N
.a]av
} '! ;Xxe5
3AuLRI
L{6Vi&I84[
public String getSSiteURL() R/c-sV
{ Wzh#dO?7
return sSiteURL; MIAC'_<-e
} gAGcbepX
<^A1.o<GN
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public void setSSiteURL(String value) *zPz)3;
{ t+WUz#i"
sSiteURL = value; 5@Xy) z
} Kv\uBMJNW
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Wf$P+i*
public String getSFilePath() ,n{|d33
{ 7}e{&\0=l
return sFilePath; %i9*2{e#~
} .TRp74
\G]vTK3
qZ+^ND(I
public void setSFilePath(String value) W(*?rA-PP
{ Y5Z<uD
sFilePath = value; z6Yx )qBE<
} ];}7 %3
#J c)v0_
pB]+c%\
public String getSFileName() Je~Ybh
{ ]M9r<x*
return sFileName; ZEU/6.
} ^5gB?V,
|f&=9%
&uTK@ G+
public void setSFileName(String value) 7;:Uv=
{ o>4GtvA*
sFileName = value; ?pF uV`Zm
} }W R?n
;=ERm=
3H/4$XJB
public int getNSplitter() <Okl.Iz>
{ ji|tc9#6
return nSplitter; v4x1=E
} yB^_dE
c3aF lxW
K0?:?>*b#
public void setNSplitter(int nCount) f9&po2Pzf
{ o4pe>hn
nSplitter = nCount; =arrp:
} olf7L%
} wTY8={p]
Jq?"?d|:
0NG<uZ
/* 2l!* o7
**Utility.java zINziAp{
*/ {B lM<
package NetFox; G^Yg[*bJ^$
z@em1W0?Z
d_}q.%*
public class Utility { >NN&j#;x~
;v1&Rs
6>B_ojj:
public Utility() |;_uN q9
{ @5\ns-%
|\~!oN
U*6)/.J
} rYMHc@a9(
+gOv5Eno-
//线程睡眠 S+(-k0
public static void sleep(int nSecond) Od:,r
{ #\fxU:z~r
try{ v81H!c.*
Thread.sleep(nSecond); n$T'gX#5
} <U() *0
catch(Exception e) CwVORf,uA
{ 42: 6=\
e.printStackTrace (); ;4 ON
} 9Iod[ x
} ]1 OZY@
r|tTDKGQ
//日志 S20L@e"U
public static void log(String sMsg) @eGJ_J
{ 2U;ImC1g
System.err.println(sMsg); tk <R|i
} eO:wx.PW
IZkQmA=
-?$Hr\
public static void log(int sMsg) z!GLug*j`
{ \L:;~L/
System.err.println(sMsg); ?xuhN G@
} J,k|_JO
} oopACE>
.UuCTH;6`
u/BCl!`
/* }vbs6u
**TestMethod.java hs"=>(P)
*/ o4"7i 9+g
package NetFox; M1/Rba Q
ZsPT!l,
t:G67^<3
public class TestMethod { C"P40VQoo
5xawa:K
(ft8,^=4
public TestMethod() _8CE|<Cn
{ ///xx/weblogic60b2_win.exe m*MfGj(
try{ .;0?r9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D^knN-nZ*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?m?DAd~ZY
SiteFileFetch fileFetch = new SiteFileFetch(bean); {\Eqo4A5}
fileFetch.start(); ul$^]ZWkI
} <Yk#MeiEp
catch(Exception e){e.printStackTrace ();} <y}`PmIM I
Qf|=xV,F
/{';\?w
} c.u$NnDU6
wYrb P11
m|)Mc VV
public static void main(String[] args) -4&SYCw
{ f"j"ZM{~U
new TestMethod(); :i&ZMH,O
} 4_E{
} ^hhJ6E_W
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