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
} 2L2 VVO
for(int i=0;i<nEndPos.length-1;i++) sS2_-X[_
{ 3@)obb
nEndPos = nStartPos[i+1]; ~XUOWY75
} /2e%s:")h
nEndPos[nEndPos.length-1] = nFileLength; bar0{!Y"
} dk_,YU'z
} kG1;]1tT#
CE#\Roi x)
xQJIM.
//启动子线程 '@TI48 J+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,?g=U8y|
for(int i=0;i<nStartPos.length;i++) c^=R8y-N
{ EZ"bW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +z-[s6q2m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MZ|\S/
nStartPos,nEndPos,i); Yb[n{.%/g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d/{Q t
fileSplitterFetch.start(); hH%,!tSx
} (*,8KLV_i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7DtIVMiK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <%z@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q.,DZp
nEndPos = " + nFileLength); (0i'Nb"
// fileSplitterFetch[nPos.length-1].start(); n%/i:Whs
ImIqD&a-h
1^C|k(t
//等待子线程结束 _>Pk8~m
//int count = 0; iJdP>x
//是否结束while循环 H9RGU~q4s[
boolean breakWhile = false; jfUJ37zNZr
b5j*xZv
XGfzEld2"
while(!bStop) D_d|=i
{ Q|Pbt(44
write_nPos(); n]+.
Utility.sleep(500); ;XG]Q<S\
breakWhile = true; BhKO_wQ?:J
L=,OZ9aA
}YQ:6I
for(int i=0;i<nStartPos.length;i++) &=6%>
{ <cYp~e%xIw
if(!fileSplitterFetch.bDownOver) &hayR_F9
{ W57&\PXYn
breakWhile = false; Is13:
break; nv"G;W
} p8=|5.
} T2wv0sHlt
if(breakWhile) {XtoiI
break; ~r<p@k=.#0
q7,^E`5EgU
<_9!
//count++; s~^*+kq
//if(count>4) td >,TW=A*
// siteStop(); .Gh%p`<
} lop uf/U0
B{p4G`$i1
yRC3 .[
System.err.println("文件下载结束！"); }W$8M>l
} i\Yl
catch(Exception e){e.printStackTrace ();} {I{3(M#"
} d$K=c1
I"1CgKYK^+
e*:}$u8a
//获得文件长度 {"m0)G,G
public long getFileSize() p1D()-
{ 9? 2
int nFileLength = -1; lUv=7" [
try{ 1}!L][(
URL url = new URL(siteInfoBean.getSSiteURL()); P-'_}*wxi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "cMNdR1^,y
httpConnection.setRequestProperty("User-Agent","NetFox"); /7gi/uh~-(
?Ko|dmX
vZ@g@zB4o0
int responseCode=httpConnection.getResponseCode(); |3;(~a)%
if(responseCode>=400) p<KIF>rf|
{ =_ y\Y@J
processErrorCode(responseCode); %cX"#+e
return -2; //-2 represent access is error >,"sHm}l%
} ,=|4:F9
` W4dx&
rjUBLY1(
String sHeader; V^n0GJNo
JrDHRIkgm
QU/fT_ORw
for(int i=1;;i++) Uk,g> LG
{ LkBZlh_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #~k[6YR 0
//Utility.log(in.readLine()); \iru7'S
sHeader=httpConnection.getHeaderFieldKey(i); /^:2<y8Ha
if(sHeader!=null) Q[PK`*2)
{ -[DWM2C$K4
if(sHeader.equals("Content-Length")) @2 =z}S3O
{ \9)#l#m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9#k0_vDoW
break; p@ygne4
} r`6:Q&&
} 5&!'^!
else XP-C
break; |]W2EV ,b
} #?Mj$ZB
} k4{:9zL1#?
catch(IOException e){e.printStackTrace ();} B +Aj*\Y.
catch(Exception e){e.printStackTrace ();} J8<J8x4
_D,eyP9P
+xp]:h|
Utility.log(nFileLength); y-B=W]E
*C6D3y
:#u}.G
return nFileLength; r_U>VT^E:
} l-.(Ez*
pu4,0bw
xWE8Wm
//保存下载信息（文件指针位置） CzVmNy)kl
private void write_nPos() KX3KM!*
{ `8:K[gp
try{ $`ztiVu3
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?6P.b6m}0
output.writeInt(nStartPos.length); *(QH{!-$s
for(int i=0;i<nStartPos.length;i++) a1c1k}
{ 2) ?q58
// output.writeLong(nPos); t-7og;^8k
output.writeLong(fileSplitterFetch.nStartPos); p[v#EyoC
output.writeLong(fileSplitterFetch.nEndPos); 9(,@aZ
} Y3',"
output.close(); qZk:mlYd
} A\$ >>Z
catch(IOException e){e.printStackTrace ();} =X(%Svnp
catch(Exception e){e.printStackTrace ();} H&4~Uo.5
} Rc[0aj:
idc4Cf+4
A\QJLWBv^$
//读取保存的下载信息（文件指针位置） 7:Ztuc]
private void read_nPos() PaO-J&<
{ $_D6_|HK
try{ E(^0B(JF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v]"L]/"
int nCount = input.readInt(); KE}H&1PjU
nStartPos = new long[nCount]; #sB,1"
nEndPos = new long[nCount]; 9&Ne+MY^%
for(int i=0;i<nStartPos.length;i++) d]wD[]
{ 86qI
nStartPos = input.readLong(); u\1>gDI)|
nEndPos = input.readLong(); H!)=y
} x_MJJ(q8g
input.close(); CN&
} *>q/WLR
catch(IOException e){e.printStackTrace ();} sZhMa>
catch(Exception e){e.printStackTrace ();} ^3]UZ@
} @;Opx."
?jO 5 9n
<l,o&p,>|c
private void processErrorCode(int nErrorCode) u0o'K9.r
{ NwlU%{7W6
System.err.println("Error Code : " + nErrorCode); -YGbfd<wq
} T:iP="?{
_.V?A*
Sq2P-y!w
//停止文件下载 ?1I GYyu!
public void siteStop() 3l1cyPv
{ jO~:<y3 =
bStop = true; X~9j$3lUBR
for(int i=0;i<nStartPos.length;i++) =L-I-e97@
fileSplitterFetch.splitterStop(); F<&!b2)ML
LnsD
Ao9R:|9
} DcD{*t?x
} 1Sz A3c
//负责部分文件的抓取 :t("L-GPW
**FileSplitterFetch.java l$xxrb9P!
*/ d_z59
package NetFox; 3=0E!e
K^l:MxO-X
Ms^dRe)
import java.io.*; mpw~hW0-
import java.net.*; ZWUP^V
3gZ8.8q3
3_$w|ET
public class FileSplitterFetch extends Thread { jXg
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IE2"rQT
String sURL; //File URL .)tSg
long nStartPos; //File Snippet Start Position XMIbUbUk-
long nEndPos; //File Snippet End Position ~Bi_7 Q
int nThreadID; //Thread's ID XGrue6ya
boolean bDownOver = false; //Downing is over 23\RJpKb
boolean bStop = false; //Stop identical 0&+k.Vg
FileAccessI fileAccessI = null; //File Access interface 9xI GV!
zYER
lSwcL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,:Z^$
{ O[^%{'
this.sURL = sURL; oqd;6[%G
this.nStartPos = nStart; _qwQ;!9
this.nEndPos = nEnd; YwEpy(}hJm
nThreadID = id; %ysZ5:X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 CY:d`4
} ~uWOdm-"[
13k !'P
!^oV #
public void run() kOwMs<1J
{ g=L]S-e
while(nStartPos < nEndPos && !bStop) 56lCwXCgA
{ YY((#"o;l
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hwYQGtjF
try{ H6*^Ga
URL url = new URL(sURL); H`hnEOyLp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xM>W2
httpConnection.setRequestProperty("User-Agent","NetFox"); _gj&$zP
String sProperty = "bytes="+nStartPos+"-"; ;*TIM%6#
httpConnection.setRequestProperty("RANGE",sProperty); S[3iA~)Z-
Utility.log(sProperty); XN=67f$Hw
,_.I\EY[
}Db[ 4
InputStream input = httpConnection.getInputStream(); 3g'S\G@
//logResponseHead(httpConnection); %8~Q!=*Iq
x&sI=5l
c,MOv7{x_
byte[] b = new byte[1024]; 7cP@jj
int nRead; <*ZJaBwWU~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4rT*tW"U
{ `3H4Ajzcc
nStartPos += fileAccessI.write(b,0,nRead); +d}E&=p_
//if(nThreadID == 1) 7w:ef0S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .~A*=
} GYxM0~:$k
8H,4kY?Z
]B"'}%>ez
Utility.log("Thread " + nThreadID + " is over!"); jdZ~z#`(!:
bDownOver = true; !)"%),>}o
//nPos = fileAccessI.write (b,0,nRead); RcG0 8p.)
} -H^oXeN
catch(Exception e){e.printStackTrace ();} mYN7kYR}<`
} <#=N m0S$
} /@ !CKh`
:o-,SrORM
)~4II.`%^
//打印回应的头信息 Mv544>:
public void logResponseHead(HttpURLConnection con) EC2+`HJ"
{ EKEjv|_)
for(int i=1;;i++) $EZN1\
{ _ nA p6i
String header=con.getHeaderFieldKey(i); iXu]e;6
if(header!=null) RpWTpT1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); '|]e<Mt-
Utility.log(header+" : "+con.getHeaderField(header)); 00I}o%akO
else Ars687WB
break; s4Sd>D7
} KH)D08
} oVA?J%EK
N7'OPTKt&
Ds#/
public void splitterStop() kIw`P[
{ ~CB[9D=
bStop = true; .7'kw]{/
} 0N[&3Ee8
d2oh/j6`TA
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} \P} p5k[
H1<>NWm!v7
3~,d+P
/* h~&gIub
**FileAccess.java UDhG :
*//文件访问(定位，写) =9oPowq
package NetFox; I}e3zf>
import java.io.*; i|w8.}0
Wcb7 ;~K
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public class FileAccessI implements Serializable{ ~<<nz9}o_
/,!qFt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +4[^!q* H
RandomAccessFile oSavedFile; s2?T5oWU
long nPos; Q~R ~xz
Q9I j\HbA"
sK{l 9
public FileAccessI() throws IOException +iRq8aS_
{ .Ha'p.
this("",0); A+y
} ;\EiM;Q]
gu#-O?B
o,U9}_|A
public FileAccessI(String sName,long nPos) throws IOException JnHo9K2.
{ !d<"nx[2`
oSavedFile = new RandomAccessFile(sName,"rw"); ,Y3W?
this.nPos = nPos; +!QJTn"3
oSavedFile.seek(nPos); ?)bS['^1)
} |mdi]TL
D9`0Dr}/2
hN['7:bQ
public synchronized int write(byte[] b,int nStart,int nLen) 3qY K_M^[
{ 5H=ko8fZ=
int n = -1; ~/mwx8~
try{ T+N|R
oSavedFile.write(b,nStart,nLen); [M.f-x:
n = nLen; d,8mY/S>w
} e[sK@jX6
catch(IOException e) |F9z,cc"
{ v9Xp97J2
e.printStackTrace (); \Mg`(,kwe
} [tMZ G%h
jTLSdul+
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return n; i)#s.6.D>
} LL|7rS|o
,J`'Y+7W
nW;g28
} aM7uBx\8 5
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"NgoaG~!YO
/* #gm)dRKm%
**SiteInfoBean.java kId n6 Wx,
*/ e/->_T(I
package NetFox; .VTy[|o
K}6dg<
Cy*|&=>j
public class SiteInfoBean { l>Ub!^;
)lJao
F)z;Z6{t4
private String sSiteURL; //Site's URL ^$&k5e/}C
private String sFilePath; //Saved File's Path rDm'Z>nTf
private String sFileName; //Saved File's Name jy]JiQB
private int nSplitter; //Count of Splited Downloading File `DT3x{}_S
8k(P,o
vD 5vbl
public SiteInfoBean() )sho*;_o
{//nSplitter的缺省值为5 :ss,Hl
//default value of nSplitter is 5 XUuu-wm:}
this("","","",5); 97K[(KE
} ljKrj
a>mm+L8y
C&++VRnm
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~rjTF!
{ 5OoN!TEM
sSiteURL= sURL; }du XC[6
sFilePath = sPath; :VF<9@t
sFileName = sName; "B_K XL
this.nSplitter = nSpiltter; cUDoN`fSl,
V/LQ<Yke
RT>{*E<I
} -Ij&
rHP%0f9:
&-5_f*{
public String getSSiteURL() _-5,zPR
{ rp5(pV7*
return sSiteURL; BUwONF
} RxMH!^
ORu2V#Z[
-{`@=U
public void setSSiteURL(String value) |Yq$sU
{ c{[q>@y pK
sSiteURL = value; 6\61~u~
} I|# 5NE6
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mrV!teP
public String getSFilePath() 3pmWDG6L
{ KFa_
return sFilePath; 1xv8gC:6
} `GXkF:f=
?YeWH WM
IF]lHB
public void setSFilePath(String value) Cuc$3l(%
{ Agrp(i"\@
sFilePath = value; kD[ r.Dma
} nI0[;'Hn,
Tr^nkD{
k1VT /u
public String getSFileName() V^Hu3aUx8
{ =}PdH`S
return sFileName; QM?#{%31
} ~Y.tz`2D
=V"(AuCVE
t'm;:J1
public void setSFileName(String value) Gn;@{x6
{ &CwFdx:Ff
sFileName = value; r=c<--_@
} 0-{tFN
#M A4
#[#KL/i)$
public int getNSplitter() m~uOXb
{ y*MF&mQ[
return nSplitter; f@co<iA
} %p X6QRt?
gNGr!3*)w
g R nOd
public void setNSplitter(int nCount) t#!yrQ..'G
{ ["}rk
nSplitter = nCount; R-^96fFBy
} r\;ut4wy
} YIR R=qpn
sl*5Y#,|1
O0>A+o[1F
/* xAggn
**Utility.java @]bPVG?d
*/ g:0#u;j^7
package NetFox; n<B<93f/
/pp1~r.s?>
j1 =`|
public class Utility { cwV]!=RtO
5[n(7;+gw
gl&5l1&
public Utility() <LRey%{q
{ ^9-&o
X>?b#Eva
n&A'C\
} ^T~gEv
CIVnCy z
//线程睡眠 -l}IZY
public static void sleep(int nSecond) [=%TnT+^9
{ _20#2i&
try{ l1]p'Liuu
Thread.sleep(nSecond); s}onsC
} `<[6YH_
catch(Exception e) z6py"J@
{ /.M+fr S
e.printStackTrace (); <W]g2>9o9
} ];%0qb
} KsrjdJx, '
^*~;k|;&
//日志 7RDDdF E!
public static void log(String sMsg) eiJ2NwR\w
{ wM_c48|d
System.err.println(sMsg); hXGwP4
} /*Qq[C
XlI!{qj|
7hy&-<
public static void log(int sMsg) rxO2QQ%V
{ fSDi-I
System.err.println(sMsg); ~:km]?lz0
} SE7WF18A
} ASPy
h d~$WV0#
wv^rS^~
/* lnGq :-
**TestMethod.java %P;Q|v6/|
*/ Quf_'
package NetFox; )bx_;9Y{
:fk2]{KTL
'8j$';&`
public class TestMethod { HG'{J^t
y0~Ia:y
5X.e*;
public TestMethod() fJZp?e"
{ ///xx/weblogic60b2_win.exe S(aZ4{a@
try{ t:LcNlN|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q !qrNa6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B^D(5
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^KB~*'DN~s
fileFetch.start(); /m _kn
} V#ev-\k}@
catch(Exception e){e.printStackTrace ();} 7m#[!%D
7j7e61 Ax
| nJZie8m
} ,@z4I0cTi\
2FD=lR?6
mW%?>Z1=>d
public static void main(String[] args) kj5Q\vr)
{ .lhn;*Yi
new TestMethod(); ,7,g%?_P
} {2`=qt2
} }6 5s'JB
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