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)); z n8ig/C
} U`_vF~el~
for(int i=0;i<nEndPos.length-1;i++) )&!@O$RS8(
{ E!l1a5qB
nEndPos = nStartPos[i+1]; 5GL+j%7
} G-?9;w'@
nEndPos[nEndPos.length-1] = nFileLength; b<78K5'
} gO!h<1!
} je3n'^m
<7] Y\{+
ioCkPj
//启动子线程 R+hS;F nh%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q$'&RG
for(int i=0;i<nStartPos.length;i++) oxXW`C<
{ 0BE^qe
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ByvqwJY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), { (,vm}iFL
nStartPos,nEndPos,i); -"K:ve(K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -\C6j
fileSplitterFetch.start(); lA 0_I"b2Y
} 6YGr"Kj &
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e`1s[ ^B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lS-i9U/,>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K"$ky,tU
nEndPos = " + nFileLength); E9-'!I!
// fileSplitterFetch[nPos.length-1].start(); IjAity.Xrq
v("vUqhx2+
*sVxjZvV
//等待子线程结束 !$#4D&T
//int count = 0; XPTB,1g+f
//是否结束while循环 ;#yz i2f
boolean breakWhile = false; &bu`\|V
Lb 4!N`l
j=>Gfo
while(!bStop) @Qozud\?
{ --)[>6)I
write_nPos(); 4jro4B`
Utility.sleep(500); RE$-{i
breakWhile = true; P~Owvs/=
0N_Da N
b"bj|qF~E
for(int i=0;i<nStartPos.length;i++) +t{FF!mL
{ `"Pd$jW
if(!fileSplitterFetch.bDownOver) z# B) b5
{ KrH;o)|
breakWhile = false; CFxs`C^
break; c7wgjQ[
} -.{7;6:(k
} 8, ^UQ5x
if(breakWhile) pl&GFf o
break; N6'Y N10
b1!%xdy_T
iJeT+}
//count++; li^E$9oWC
//if(count>4) R8*4E0\br
// siteStop(); XWV~6"
} i%w'Cs0y
PeaD]
n\U6oJN
System.err.println("文件下载结束！"); ly+7klQ;.
} )\^OI:E
catch(Exception e){e.printStackTrace ();} ?zqXHv#x
} nr;/:[F
4r$t}t gX
JG4I-\+H
//获得文件长度 4esf&-gG
public long getFileSize() %## bg<
{ +eg$Z]Lht
int nFileLength = -1; iZyhj%#
try{ -$!`8[fM
URL url = new URL(siteInfoBean.getSSiteURL()); 1$]4g/":o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i!@L`h!rw
httpConnection.setRequestProperty("User-Agent","NetFox"); J*IC&jH:
9X/c%:)\=
h/W@R_Y
int responseCode=httpConnection.getResponseCode(); eYLeytF]Uy
if(responseCode>=400) 2&S*> (
{ OB FG!.)
processErrorCode(responseCode); QK)"-y}"g
return -2; //-2 represent access is error *"2TT})
} M#c.(QdF
TL lR"L5
I@76ABu^
String sHeader; ?aR)dQ
|#fqHON
$yS7u
for(int i=1;;i++) x<W`2Du
{ 481J=8H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q{?Po;\D
//Utility.log(in.readLine()); W7r1!/ccj
sHeader=httpConnection.getHeaderFieldKey(i); Ju4={^#
if(sHeader!=null) Lwm2:_\_b
{ cPZD#";f
if(sHeader.equals("Content-Length")) A6v<+`?
{ o[pv.:w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {p@uH<)
break; ve;#o<
} a/Z >-
} fS+Ga1CsH
else 9&a&O Z{
break; 8DHohhN
} x2/L`q"M?=
} z'OY6
catch(IOException e){e.printStackTrace ();} (lBgWz
catch(Exception e){e.printStackTrace ();} b.V\EOk
)D?\ru H
bAS('R;4
Utility.log(nFileLength); |>(d^<nR^v
Q[+&n*
1ga.%M*
return nFileLength; SUwSZ@l^|
} n<\ WVi
UZ#Yd|'PD
F=)9z+l#
//保存下载信息（文件指针位置） G Xx7/X
private void write_nPos() Ct2m l
{ Nb;xJSlox
try{ K8xwPoRL
output = new DataOutputStream(new FileOutputStream(tmpFile)); gw[\7
output.writeInt(nStartPos.length); r#ES|
for(int i=0;i<nStartPos.length;i++) |L|)r)t
{ g_'F(An
// output.writeLong(nPos); {hYH4a&Hb
output.writeLong(fileSplitterFetch.nStartPos); T1'8<pJ^
output.writeLong(fileSplitterFetch.nEndPos); n-iy;L^b
} }@Rq'VPZd
output.close(); hwgLJY?
} "A\.`*6
catch(IOException e){e.printStackTrace ();} #lDf8G|ST~
catch(Exception e){e.printStackTrace ();} Ucnj7>+"
} A0Z<1|6r*
?S&pq?
i=67
//读取保存的下载信息（文件指针位置） l-|hvv5g
private void read_nPos() t[gz#'
{ `@.
try{ I{>U7i 5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S-)mv'Al'F
int nCount = input.readInt(); R1.No_`PHq
nStartPos = new long[nCount]; :5 XNV6^|
nEndPos = new long[nCount]; O7r<6(q(
for(int i=0;i<nStartPos.length;i++) 7+^9"k7
{ nT UKA
nStartPos = input.readLong(); Ph[P$: 9
nEndPos = input.readLong(); v.Fq.
} H"v3?g`S%
input.close(); mDJF5I
} GJlkEWs
catch(IOException e){e.printStackTrace ();} NyHHK8>
catch(Exception e){e.printStackTrace ();} QP+zGXd}(
} UuDT=_1Sh
Twscc"mK
NpS*]vSO
private void processErrorCode(int nErrorCode) w[g(8#*
{ ~lB im$o
System.err.println("Error Code : " + nErrorCode); pUs:r0B
} &S\q*H=}i
V=#L@ws
|Ld/{&Qr
//停止文件下载 ^a9v5hu
public void siteStop() zk)9tm;i{
{ I'"b3]DXG
bStop = true; H)XHlO^
for(int i=0;i<nStartPos.length;i++) 8<cD+Jtj
fileSplitterFetch.splitterStop(); K@ZK@++
1.+w&Y5
WJH)>4M#
} REd"}zDI
} We^!(G
//负责部分文件的抓取 j8lWra\y
**FileSplitterFetch.java O0`k6$=6r
*/ k_A.aYe
package NetFox; yc|j]?
C[cNwvz
&r0b~RwUv
import java.io.*; $s]c'D)
import java.net.*; WU}?8\?U%
wd4wYk\
-C9_gZ
public class FileSplitterFetch extends Thread { P%Fkd3e+
\k6Ho?PL
.(!> *ka|
String sURL; //File URL m@K5eh
long nStartPos; //File Snippet Start Position k!/"J ;
long nEndPos; //File Snippet End Position p h[ ^ve
int nThreadID; //Thread's ID d',OQ,~{
boolean bDownOver = false; //Downing is over }Qjp,(ye
boolean bStop = false; //Stop identical e}qG_*
FileAccessI fileAccessI = null; //File Access interface >BC?%|l
^X$k<nA;
"^A4!.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B1]5%B
{ ?y( D_NtL
this.sURL = sURL; ,3^gB,ka
this.nStartPos = nStart; _c}@Fi+E
this.nEndPos = nEnd; ,X Zo0!
nThreadID = id; u!in>]^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _I;+p eq
} dQfVdqg
}{Y)[w#R
d/>owCwQ
public void run() RhM]OJd'
{ #BQ7rF7CNE
while(nStartPos < nEndPos && !bStop) voRr9E*n
{ y~)rZ-eSB
R:+2}kS5e{
x\qS|q\N
try{ }]w/`TF
URL url = new URL(sURL); 6< x0e;>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); # 4E@y<l$
httpConnection.setRequestProperty("User-Agent","NetFox"); 2ye^mJ17
String sProperty = "bytes="+nStartPos+"-"; J[9yQ
httpConnection.setRequestProperty("RANGE",sProperty); %JBFG.+
Utility.log(sProperty); ZA@QP1
HJpkR<h
h>v;1QO9D
InputStream input = httpConnection.getInputStream(); K5U=%z
//logResponseHead(httpConnection); $YvT* T$_
O!+LM{> F
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byte[] b = new byte[1024]; ^p#f B4z
int nRead; 6 W/S?F~{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O_8ERxj g]
{ 'Z LGt#
nStartPos += fileAccessI.write(b,0,nRead); @MIBW)P<
//if(nThreadID == 1) a' "4:(L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SX)giQLU
} l1^/Q~u
l,}{Y4\G
82Fq}N <
Utility.log("Thread " + nThreadID + " is over!"); V6l*!R
bDownOver = true; }5gAxR,
//nPos = fileAccessI.write (b,0,nRead); X%W_cb2
} O/\L0\T
catch(Exception e){e.printStackTrace ();} [.DSY[!8U
} WjZJQK
} o)'u%m
zI/)#^SQ
Q!/<=95E
//打印回应的头信息 q;3,}emg
public void logResponseHead(HttpURLConnection con) G)\s{qk
{ $Gb] K{e
for(int i=1;;i++) "'H$YhY]
{ w)-@?jN
String header=con.getHeaderFieldKey(i); (g,lDU[=
if(header!=null) ^,zE Nqg7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Mw!?2G[|
Utility.log(header+" : "+con.getHeaderField(header)); fLK*rK^{"
else \3dMA_5
break; A0.)=q
} ul~>eZ
} hGi"=Oud2
mfOr+
H=]$9ZH!
public void splitterStop() "~x\bSY
{ RWmQP%A}aw
bStop = true; h.c<A{[I6c
} :T3I"
vPEL'mw/3#
{snLiCl
} 7uJy<O
GutH}Kz"&
XNwY\y
/* Z"Z&X0Oj
**FileAccess.java 6}mbj=E`
*//文件访问(定位，写) P8!Vcy938
package NetFox; rb%P30qc4
import java.io.*; !o~% F5|t
o:#l r{
Vnuz! 6.
public class FileAccessI implements Serializable{ d.tjLeY
2D`@$)KL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )c5M;/s
RandomAccessFile oSavedFile; aWek<Y~+
long nPos; t/WauY2JUC
a*hOT_;#
/Ik_U?$*
public FileAccessI() throws IOException `kIzT!HX
{ o!L1Qrh
this("",0); Zoj.F
} s`xp6\$
> C{^{?~u
o%X_V!B{V
public FileAccessI(String sName,long nPos) throws IOException >x@]wsj
{ <ro0}%-z>M
oSavedFile = new RandomAccessFile(sName,"rw"); 8#'<SB
this.nPos = nPos; ~\4l*$3(^
oSavedFile.seek(nPos); AuUT 'E@E
} E4[ |=<
1;3oGuHj8
"C.'_H!Ex
public synchronized int write(byte[] b,int nStart,int nLen) wx -NUTRim
{ }$#e&&)n
int n = -1; J}EQ_FC"$
try{ QE84l
oSavedFile.write(b,nStart,nLen); A?|KA<&m#u
n = nLen; LP_d}ve
} 9_JK.
catch(IOException e) !1+L0,I6
{ #9O *@
e.printStackTrace (); hJ.XG<?]$
} YNc%[S[u^1
2/=CrK
K6~N{:.s
return n; ^~-i>gTD
} ]8ua>1XS
kLMg|48fdI
[Av87!kJ!X
} MHVqRYz
0z&3jWWY@
Y oNg3
/* iU9de
**SiteInfoBean.java jC ,foqL
*/ . l RW
package NetFox; pA='(G
|@]J*Kh
T9KzVxHp5
public class SiteInfoBean { vrm[sP
LT!B]y
oc?,8I[P5
private String sSiteURL; //Site's URL t9&)9,my
private String sFilePath; //Saved File's Path !1C3{
private String sFileName; //Saved File's Name zBay 3a
private int nSplitter; //Count of Splited Downloading File b=:AFs{
F)j-D(c4
e{:P!r aM
public SiteInfoBean() 6/hY[a!
{//nSplitter的缺省值为5 24Z7;'
//default value of nSplitter is 5 ,IA0n79
this("","","",5); _xI'p6C
} yX$I<L<Suz
+Q If7=
apa~Is1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) T.<eriv
{ (u@[}!
sSiteURL= sURL; GbwcbfH
sFilePath = sPath; <_uLf9ja
sFileName = sName; Sh=E.!
this.nSplitter = nSpiltter; Ym(^ih
jRm:9`.Q
O}MY:6Pe
} Z%D*2wm4
.S`Ue,H
r7c(/P^$G
public String getSSiteURL() =#&K\
{ Ht5 %fcD
return sSiteURL; j.uN`cU!
} *SzP7]1m
A5!jrSyv
SGZOfTcY
public void setSSiteURL(String value) Z 7t0=U
{ pL]C]HGv
sSiteURL = value; R,C)|*ef
} 0AY23/
7B_;YT
0L$v7, 5
public String getSFilePath() 'jZ2^
{ S5@/;T
return sFilePath; d;|e7$F'
} .6!IO^`[
$yIcut7
df nmUE
public void setSFilePath(String value) =$}P'[V
{ @/lLLGrZ"
sFilePath = value; n&iWYECz
} *DLv$/(0
'&W`x5`t
CM>/b3nOW
public String getSFileName() 'X_iiR8n@p
{ U`,&Q]
return sFileName; i)1E[jc{p!
} u'd+:uH
z:^Kr"=n
>a%NC'~rc
public void setSFileName(String value) LbJtU!
{ +e)So+.W
sFileName = value; /&$'v:VB
} R$K.;
i6kW"5t
yrdJX
public int getNSplitter() Fla[YWS
{ N;F1Z-9
return nSplitter; _0)#-L>xKF
} H.7gSB1
{v+i!a'+
wHBkaPO!
public void setNSplitter(int nCount) uw LT$
{ //JF$o=)D
nSplitter = nCount; *wwLhweQ5W
} (i|`PA
} R# 8D}5[&
doFp53NhV
3LG}x/l
/* @?aNvWeavH
**Utility.java 8!TbJVR
*/ )"&-vg<
package NetFox; .'lc[iI9)d
GLwL'C'591
NRcg~Nu
public class Utility { 9'3bzhT$
!#rZeDmw
<.l5>mgkCw
public Utility() 56G5JSB=\
{ MQQiQ 2
W$EX6jTGI
u7^Z7; J
} q .tVNKy%
VDPqI+z
//线程睡眠 Fy`VQ\%7t
public static void sleep(int nSecond) zO2<Igb
{ bsr
try{ U>e@m?
Thread.sleep(nSecond); Wxjk}&+pVa
} vD:.1,72
catch(Exception e) n-Dr/c4
{ y3 LWh}~E
e.printStackTrace (); cC"7Vt9b
} j+_g37$:
} :7W5R
eP&K]#
//日志 tK g%5;v
public static void log(String sMsg) xtpD/,2
{ twf;{lZ(
System.err.println(sMsg); xdYjl.f
} 2J9eeN
6@H&S
,m3AVHa*G
public static void log(int sMsg) I #1_
{ }9Y='+.%^
System.err.println(sMsg); U!3nn#!yE
} +(PtOo.
} GZI[qKDfB
YX^{lD1Jj
5kC#uk
/* "D3JdyO_S
**TestMethod.java A.35WGu&:
*/ qpp:h_E
package NetFox; YV!!bI
oJ6 d:
"Hgn2o.;5
public class TestMethod { y,Dfqt
6TfXz2D'J
sUj#:X
public TestMethod() yQou8P=%
{ ///xx/weblogic60b2_win.exe JN|<R%hy
try{ B-@f.NO/s
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #GWQ]r?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >4h4t/G
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;R2(Gb
fileFetch.start(); ;GH(A=}/Y
} V#3VRh
catch(Exception e){e.printStackTrace ();} 2cy{d|c
;uba
)>TA|W]@
} K =7(=Y{
jg%D G2
~PoGuj2wA
public static void main(String[] args) Dtr'X@U
{ veK
new TestMethod(); 9^c_^-8n<}
} V!ajD!00
} fl)Oto7
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