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)); WyVFhAuU
} zu&5[XL
for(int i=0;i<nEndPos.length-1;i++) (Da/$S.
{ $8o(_8Q)
nEndPos = nStartPos[i+1]; L+Yn}"gIs
} ]kq{9b';
nEndPos[nEndPos.length-1] = nFileLength; Qj~m;F!
} d_=@1JM>
} 8RWfv}:X
%)T>Wn%b]v
')t :!#
//启动子线程 +[*VU2f t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %o9@[o .]
for(int i=0;i<nStartPos.length;i++) `E>HpRcxD
{ aO('X3?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w\k|^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C J S
nStartPos,nEndPos,i); _x 'R8/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pkpD1c^
fileSplitterFetch.start(); <m9hM?^q
} SV16]Vc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =8$//$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Kdk0#+xtP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1eQ9(hzF
nEndPos = " + nFileLength); ~C=I{qzF+
// fileSplitterFetch[nPos.length-1].start(); TSqfl/UI
D_ xPa
lxy_O0n
//等待子线程结束 |t*(]U2O0
//int count = 0; ;NH5 L,
//是否结束while循环 9Y!N\-x`
boolean breakWhile = false; B1T:c4:N
:@)UI,
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while(!bStop) =3OK3|
{ QU^*(HGip
write_nPos(); r#iZ FL3q
Utility.sleep(500); mZ 39 s
breakWhile = true; dt(~)*~R
ia 1Sf3
!!Z#'Wq
for(int i=0;i<nStartPos.length;i++) 4s nL((
{ zb.^ _A
if(!fileSplitterFetch.bDownOver) ;EbGW&T
{ !spp*Q)#\
breakWhile = false; Ig75bZz
break; ^%|,G:r
} M*FUtu
} P:h;"
if(breakWhile) tFt56/4
break; 5vs~8|aRo
nf&PDv1
Bz<T{f
//count++; C,7d
//if(count>4) bh|M]*Pq
// siteStop(); s.I%[kada
} eznt "Rr2
Hs/ aU_
\"Z^{Y[,;
System.err.println("文件下载结束！"); AE`X4q
} *,<A[XP
catch(Exception e){e.printStackTrace ();} vdw5T&Q{{C
} I|69|^
K}"xZy Tm1
x8k7y:
//获得文件长度 Qd;P?W6
public long getFileSize() HE58A.Q&
{ D ]Q,~Y&'
int nFileLength = -1; a0I+|fR
try{ 52?zBl`|
URL url = new URL(siteInfoBean.getSSiteURL()); 1=(jpy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -V0_%Smc
httpConnection.setRequestProperty("User-Agent","NetFox"); HA&7 ybl
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Z-|.j^n
int responseCode=httpConnection.getResponseCode(); 0JzH dz
if(responseCode>=400) c} )U:?6
{ 3/c3e{,!
processErrorCode(responseCode); K ;\~otR^
return -2; //-2 represent access is error 2Ya)I k{
} lM1~K
YoyJnl.?u
"1O!Ck_n
String sHeader; I?`}h}7.
nZZNx
y4*i V;"
for(int i=1;;i++) f%vJmpg
{ !v/5G_pr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2N*XzVplN
//Utility.log(in.readLine()); Q#"p6ZmI
sHeader=httpConnection.getHeaderFieldKey(i); Z(DCR/U=(>
if(sHeader!=null) d: D`rpcC
{ oV"d%ks
if(sHeader.equals("Content-Length")) &*2\1;1tB
{ sd4eJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fkf69,+"]
break; V]I@&*O~r
} Gl8D GELl;
} R_9&V!fl
else \kSoDY`l&
break; Zoe>Ow8mE`
} y/=:F=H@w
} :})(@.H
catch(IOException e){e.printStackTrace ();} Z]?Tx2|7
catch(Exception e){e.printStackTrace ();} N(i%Oxp1
q#LB 2M
DUH\/<^g
Utility.log(nFileLength); ZK:dhwer
wM.z/r\p
(NfP2E|B
return nFileLength; tUX4#{)q(j
} F6>K FU8
.*XELP=BT
EUBJnf:q
//保存下载信息（文件指针位置） +;z^qn
private void write_nPos() WP7RX|7
{ ;R[ xo!
try{ &Tz@lvOv%
output = new DataOutputStream(new FileOutputStream(tmpFile)); vByt_X
output.writeInt(nStartPos.length); 8Aq [@i
for(int i=0;i<nStartPos.length;i++) t^_0w[
{ FY;\1bt<<
// output.writeLong(nPos); MTBHFjXO
output.writeLong(fileSplitterFetch.nStartPos); ,TeJx+z^
output.writeLong(fileSplitterFetch.nEndPos); )Ve-)rZ
} V~#e%&73FH
output.close(); 3OnIAk3
} <JtH/oN
catch(IOException e){e.printStackTrace ();} OAigq6[,
catch(Exception e){e.printStackTrace ();} Zop3[-
} Mdk(FG(
bVfFhfh*
yx5F]Z<M2
//读取保存的下载信息（文件指针位置） 1.S7MSpTV
private void read_nPos() W,sU5sjA
{ 8yW8F26
try{ wyzx9`5~d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /<[S> ;!kr
int nCount = input.readInt(); &6]+a4
nStartPos = new long[nCount]; '?| (QU:)F
nEndPos = new long[nCount]; feJzX*u
for(int i=0;i<nStartPos.length;i++) 9Z?P/ o
{ M:t!g%
nStartPos = input.readLong(); /#mq*kNIM6
nEndPos = input.readLong(); .II*wKk
} { 'A`ram
input.close(); H~Z$pk%
} qY,z,oAF
catch(IOException e){e.printStackTrace ();} v[$-)vs*ag
catch(Exception e){e.printStackTrace ();} C]@v60I
} :r4]8X-
}"} z7Xb0
So?.V4aD_
private void processErrorCode(int nErrorCode) 3=[#(p:
{ W&M=%
System.err.println("Error Code : " + nErrorCode); |gXtP-
} N$'/J-^
2!-?
oJ\)-qSf
//停止文件下载 (CUrFZT$
public void siteStop() 1Yr&E_5/
{ N5W;Zx]
bStop = true; yH`4sd
for(int i=0;i<nStartPos.length;i++) !-G'8a|7
fileSplitterFetch.splitterStop(); ( mV*7Z
4Vv~
u_kcuN\Sq
} ceiUpWMu,
} k8>(-W"A
//负责部分文件的抓取 }s*H|z
**FileSplitterFetch.java VSm[80iR0
*/ 8]SJ=c"}Xf
package NetFox; $? 'JePC
'*4>&V.yX
*[ ' n8Z
import java.io.*; i4sd29v
import java.net.*; D8S?xK7[
qcN{p7=0
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public class FileSplitterFetch extends Thread { ~*R:UTBtw
_:RQ9x'
gK&MdF*
String sURL; //File URL ,(1n(FZ
long nStartPos; //File Snippet Start Position !yUn|v>&p
long nEndPos; //File Snippet End Position ` u|8WK:
int nThreadID; //Thread's ID B: '}SA{
boolean bDownOver = false; //Downing is over 6CQ.>M:R
boolean bStop = false; //Stop identical $5(_U
FileAccessI fileAccessI = null; //File Access interface -|1H-[Y(
w@K4u{|
W|~Jl7hs8Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;HKb
{ 4blw9x N
this.sURL = sURL; It5U=PU
this.nStartPos = nStart; )^Ha?;TS
this.nEndPos = nEnd; iTX:*$~I
nThreadID = id; 1\'?.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tVAWc$3T
} ;f]p`!] 3
h;q=<[h\
m=saUhI*9
public void run() {"^LUw8fd
{ q+j.)e
while(nStartPos < nEndPos && !bStop) s=[Tm}[
{ uq/z.m
Sio> QL Y
,^Cl?\9"
try{ +2DzX/3
URL url = new URL(sURL); o+NPe36
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 73n|G/9n[
httpConnection.setRequestProperty("User-Agent","NetFox"); 4yZ'+\ +I
String sProperty = "bytes="+nStartPos+"-"; `&3hfiI}
httpConnection.setRequestProperty("RANGE",sProperty); For`rfR
Utility.log(sProperty); |E& Fe8
@Feusprs
I "8:IF
InputStream input = httpConnection.getInputStream(); v jTs[eq>
//logResponseHead(httpConnection); YsX&]4vzm
2yB@)?V/
n;Nr[hI
byte[] b = new byte[1024]; *qX!
int nRead; p"xti+2,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o{W4@:Ib
{ t)#dR._q
nStartPos += fileAccessI.write(b,0,nRead); .o27uB.
//if(nThreadID == 1) '}nH\?(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S.: m$s
} U@;W^Mt
gY\g+df-
r Jo8|
Utility.log("Thread " + nThreadID + " is over!"); V`ODX>\
bDownOver = true; cWNZ +Q8Y
//nPos = fileAccessI.write (b,0,nRead); `6R.*hq
} [lU0TDq
catch(Exception e){e.printStackTrace ();} MD"a%H#p
} NWSm
} )aV\=a |A
"mbjS(-eg
}NH\Q$IU
//打印回应的头信息 *btLd7c%
public void logResponseHead(HttpURLConnection con) Q|gw\.]$&[
{ X@["Jjp
for(int i=1;;i++) Z+gG.|"k
{ '8k{\>
String header=con.getHeaderFieldKey(i); '7Ad:em
if(header!=null) A^m]DSFOO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^|b]E
Utility.log(header+" : "+con.getHeaderField(header)); ZqDanDM
else vb&1 S
break; =XRTeIZ
} &Zzd6[G+
} +vDEDOS1
N7wKaezE
dy}O6
public void splitterStop() QbN7sg~~
{ slQxz;t
bStop = true; cC4 2b2+
} GlVb|O"
/LH# 3
n?UFFi+a
} Gp l
OI8Hf3d=
=do*(
/* HsF8$C$z
**FileAccess.java !R b
*//文件访问(定位，写) ~x(1g;!^
package NetFox; E43Gk!/|(
import java.io.*; Wl29xY}`{!
We8n20wf<
L~Hl?bK
public class FileAccessI implements Serializable{ h/LlH9S:!
^(Y}j8sj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \68x]q[
RandomAccessFile oSavedFile; Dc1tND$X3g
long nPos; 2cB){.E
<n+]\a97*
x5X;^.1Fr
public FileAccessI() throws IOException >qqI6@h]c
{ Juhi#&`T
this("",0); #1-2)ZO.
} _EusY3q
7])cu>/
o94]:$=~
public FileAccessI(String sName,long nPos) throws IOException 9 rMP"td
{ <[oPh(!V
oSavedFile = new RandomAccessFile(sName,"rw"); 5z T~/6-(
this.nPos = nPos; ]Qu.-F#g
oSavedFile.seek(nPos); 3iKy>
} \ZOH3`vq
lDWg%pI+
+WH|nV~lQ
public synchronized int write(byte[] b,int nStart,int nLen) #W]4aZ1
{ #A:+|{H"
int n = -1; ]N& Y25oT5
try{ #GlQwk3
oSavedFile.write(b,nStart,nLen); 5n1aRA1
n = nLen; ZCcKY6b
} sOf;I]E|
catch(IOException e) 1DTA Dh0
{ t_+Xt$Q7C
e.printStackTrace (); ='\Di '*
} ./KXElvQ%
e7$ZA#A_5v
6m\MYay
return n; QAk.~ob
} wnPg).
liuw!
yu~o9
} AeZ__X
/uNgftj
y8!#G-d5
/* lQq&tz,
**SiteInfoBean.java Eq\PSa=gz
*/ fqY;>Z
package NetFox; `w;8xD(
fPA5]a9
2VZdtz
public class SiteInfoBean { JO&~mio
xh90qm
>QcIrq%=
private String sSiteURL; //Site's URL Vzmw%f)_+
private String sFilePath; //Saved File's Path 7<Yf
private String sFileName; //Saved File's Name L3@upb
private int nSplitter; //Count of Splited Downloading File Ld9YbL:
$*k9e^{S
2C&G'@>
public SiteInfoBean() AWG;G+
{//nSplitter的缺省值为5 O'i!}$=g
//default value of nSplitter is 5 -,Oq=w*EV
this("","","",5); w y\0o
} J?1U'/Wx2
"J_#6q*
p!_3j^"{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [2l2w[7Rid
{ <aPbKDF~V
sSiteURL= sURL; nRSiW*;R
sFilePath = sPath; kLfk2A;'i
sFileName = sName; Y+kfMAv
this.nSplitter = nSpiltter; kgl7l?|O
&| guPZ
6 o!*bWh
} ' ~F
q\r@x-&g+
;dR4a@
public String getSSiteURL() xis],.N
{ })#SjFq<V
return sSiteURL; iL6Yk @
} ,P.yl~'Al
$-Yq?:
q-lejVS(g
public void setSSiteURL(String value) ?r}'0dW
{ YR? ujN
sSiteURL = value; V:Lq>rs#
} 8=T[Y`;x
#sRkKl|
|RS(QU<QE
public String getSFilePath() \Aa{]t
{ OBm#E}
return sFilePath; brpsZU
} ToXgl4:kd
!VoAN5#;
R2`-*PZ_
public void setSFilePath(String value) (]}52%~
{ >69-[#P!
sFilePath = value; 6 *GR_sMm
} Ks>l=5~v|
S5(VdMd"^
6oA2"!u^w
public String getSFileName() I%Yeq"5RB
{ WW&agr
return sFileName; +k<0:Fi
} ^fq^s T.$
v{44`tR
[/+}E X
public void setSFileName(String value) = 9K5f#;e
{ `v"p""_H
sFileName = value; 5IJm_oy
} p\).zuEf.
`m_('N
z=[?&X]O9b
public int getNSplitter() 1<(('H
{ gT&s &0_7
return nSplitter; ~_GW
} |~d8j'rt
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DKnlbl1^?
public void setNSplitter(int nCount) _t7}ny[
{ 5%#V>|@e#
nSplitter = nCount; nPRv.h
} xJ(}?0h-X
} n8RE
a@v}j&
O>tz;RU
/* ,"xr^@W
**Utility.java )xxpO$
*/ \ y}!yrQ
package NetFox; _+*+,Vx
vP.^j7wB
\&jmSa=]l
public class Utility { 7ZR0cJw;
VsjE*AJpe
TRJ5m?x
public Utility() "IuHSjP
{ vjz 'y[D
AL{r/h
hVe39BBtO
} g=)OcTd#
ZT d)4f
//线程睡眠 b uOpHQn
public static void sleep(int nSecond) *Ud=x^JxO
{ Ucqn3&
try{ dVKctt'C
Thread.sleep(nSecond); tE(_Cg
} sgfci{~
catch(Exception e) 9h/JW_
{ }|9!|Q
e.printStackTrace (); ?qJt4Om
} LLD#)Jl{?
} 7)zF8V
xN +Oca
//日志 3[r9v!l
public static void log(String sMsg) Ej#pM.
{ |?\J,h
System.err.println(sMsg); *m6h(8(7Z
} rUxjm\
3k_bhK zI
s,|"s|P
public static void log(int sMsg) Tg yY 9
{ KSgYf;
System.err.println(sMsg); (`)ZR%i
} S-2@:E
} vhE^jS<Tg
M$$Lsb [
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/* CwdeW.A"j
**TestMethod.java h#~\-j9>
*/ Qk[YF
package NetFox; 08MY=PC~R
(,XbxDfM
VBq|j"o0"
public class TestMethod { N_liKhq
kesuM3
C;\R 62'
public TestMethod() 66C_XT
{ ///xx/weblogic60b2_win.exe 1a]QNl_x
try{ UNF@%O4_T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DcRvZH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E5QQI9ea
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZGsI\3S
fileFetch.start(); y"T(Unvc
} KJYcP72P
catch(Exception e){e.printStackTrace ();} HaA2y
t$EL3U/(
+aZcA#%
} (b#4Z
?8!\VNC.
3k# h!Z
public static void main(String[] args) G/N1[)
{ E2i'lO\P
new TestMethod(); :>K8oE
} Y_= ]w1
} *b,4qMr
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