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)); c,FZ{O@
} 0artR~*}
for(int i=0;i<nEndPos.length-1;i++) g&?{^4t]
{ DW0N}>Gp*
nEndPos = nStartPos[i+1]; L(t!C~3
} a?8boN(
nEndPos[nEndPos.length-1] = nFileLength; 5 =Op%
} W>y&
} <7Ry"z6g;
/#g P#Z%
W*^_Ul|
//启动子线程 PHxNo)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wL~-k
for(int i=0;i<nStartPos.length;i++) HJt@m &H|
{ 8\Kpc;zb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n'qWS/0U=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), BKk+<#Ti
nStartPos,nEndPos,i); K7=>o*p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,U?^u%
fileSplitterFetch.start(); A#8J6xcSrL
} bO+]1nZ.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <KBS ;t="1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a9g~(#?a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (qDPGd*1
nEndPos = " + nFileLength); p&k%d, *
// fileSplitterFetch[nPos.length-1].start(); kV@?Oj.&I,
rBZ0Fx$/[
KuZZKh
//等待子线程结束 sny$[!)
//int count = 0; U%rq(`;
//是否结束while循环 PM`iqn)@
boolean breakWhile = false; ;C,t`(
usR+ZQaA
c;.jo?RR2
while(!bStop) "2z&9`VIY
{ a7n`(}?Y
write_nPos(); !4+ FN)
Utility.sleep(500); n.OsmCRN;
breakWhile = true; Hb3t|<z
__|Y59J%
bkFO4OZd
for(int i=0;i<nStartPos.length;i++) @wcrtf~{)&
{ U<I]_]
if(!fileSplitterFetch.bDownOver) lx:.9>
{ g9@H4y6fe=
breakWhile = false; pch8A0JAl)
break; <kKuis6h
} pMd!Jl#(N
} X"g`hT"i
if(breakWhile) )>,ndKT~
break; }h1y^fuGi
-8:/My
C2H2*"
//count++; W#kd[Wi
//if(count>4) <RuLIu
// siteStop(); {'sp8:$a
} %\T#Ik~3
5O[\gd-
#@L5yy2
System.err.println("文件下载结束！"); \1<8'at
} ~(\.j=x
catch(Exception e){e.printStackTrace ();} B["jndyr
} ca<OG;R^
'Lh nl3
6'Q*SO;1gh
//获得文件长度 lP*p7Y '
public long getFileSize() Og7^7))
{ $},_O8R
int nFileLength = -1; N"s"^}M\
try{ Jw0I$W/
URL url = new URL(siteInfoBean.getSSiteURL()); wizLA0W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eI98J"h%?
httpConnection.setRequestProperty("User-Agent","NetFox"); @*BVS'\
IO7cRg'-F
lC@wCgc
int responseCode=httpConnection.getResponseCode(); `*3;sq%`
if(responseCode>=400) OV|n/~
{ s*R UYx
processErrorCode(responseCode); XbIxGL
return -2; //-2 represent access is error U#:N/ts*(
} X 4\V4_
Ffig0K+`
(L`IL e*
String sHeader; ndu$N$7+
b8**M'k
9SXpZ*Sx
for(int i=1;;i++) 3hcWR'|
{ <[vsGUbc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f`YHZ O
//Utility.log(in.readLine()); 49= K]X
sHeader=httpConnection.getHeaderFieldKey(i); kn+@)3W:*
if(sHeader!=null) |E&|6h1
{ .EZ8yJj1Q
if(sHeader.equals("Content-Length")) ssAGWP
{ ?(M$r\\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); baGV]=j
break; `jec|i@oO
} .|0$?w
} ^%O$7*
else =R*IOJ
break; p-*{x
} cZ3A~dTOR
} A3|2;4t
catch(IOException e){e.printStackTrace ();} mbHMy[R
catch(Exception e){e.printStackTrace ();} NfZC}
+xQj-r)-
g){gF(
Utility.log(nFileLength); @(IA:6GN
4U3 `g
n.Y45(@E
return nFileLength; Zt}b}Bz
} -$I$zo
&FG0v<f5Pv
9Y?``QBN
//保存下载信息（文件指针位置） 5%+epzy
private void write_nPos() G 2uM6
{ . LeS-
try{ 2 ,krVb?<
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?*6Q;.f<
output.writeInt(nStartPos.length); BwAmNW&i
for(int i=0;i<nStartPos.length;i++) {vk%&{D0)
{ N'0nt]&a
// output.writeLong(nPos); \H 5t-w=
output.writeLong(fileSplitterFetch.nStartPos); h6?o)Q>N
output.writeLong(fileSplitterFetch.nEndPos); pZ]&M@Ijp
} <) -]'@*c
output.close(); 5=V29
} t ?05
catch(IOException e){e.printStackTrace ();} 5"bg8hL
catch(Exception e){e.printStackTrace ();} [AYJ(H/
} zb s7G
VVfTFi<
Zzmo7kFx3
//读取保存的下载信息（文件指针位置） GC|V>| tz#
private void read_nPos() %vbov}R
{ _+Z5qUmQ
try{ fKO@Qx]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KN&|&51p}
int nCount = input.readInt(); 5Rp mR
nStartPos = new long[nCount]; bK{ VjXF
nEndPos = new long[nCount]; &'Xgf!x
for(int i=0;i<nStartPos.length;i++) ?v`24p3PC
{ X9?0`6Li
nStartPos = input.readLong(); HY;kV6g{P
nEndPos = input.readLong(); /J9Or{#r
} PKd'lo
input.close(); X{:3UTBR
} ,;Uf>8~
catch(IOException e){e.printStackTrace ();} rr>6;
catch(Exception e){e.printStackTrace ();} K5z<n0X ~
} OTNI@jQ)
_Ud!tK*H
+pQ3bX
private void processErrorCode(int nErrorCode) A)&CI6(
{ qpzyl~g:C
System.err.println("Error Code : " + nErrorCode); M!X^2
} |io)?`pj
-Rx;"J.H
PEaZ3{-
//停止文件下载 :ciD!Ly
public void siteStop() -Ir>pY\!
{ bDD29
bStop = true; E33WT{H&_'
for(int i=0;i<nStartPos.length;i++) 'T7Y5X80$j
fileSplitterFetch.splitterStop(); UID`3X
bfYVA2=Z
d. ZfK
} L-zU%`1{M
} $LcMG,8%_
//负责部分文件的抓取 b1G6'~U-
**FileSplitterFetch.java =J]M#6N0
*/ 9W-1P}e,
package NetFox; i 1Kq(7
\GKR(~f
h8-uI.RZ
import java.io.*; }a#=c*+_
import java.net.*; (Ffa{Tt!
wc\`2(
TX7dwmt)N
public class FileSplitterFetch extends Thread { sHPj_d#
=(~ZmB\
/82E[P"}6R
String sURL; //File URL b$- g"F
long nStartPos; //File Snippet Start Position b5ul|p
long nEndPos; //File Snippet End Position J*m7 d4^
int nThreadID; //Thread's ID &wN}<Ge6
boolean bDownOver = false; //Downing is over r%NzKPW'
boolean bStop = false; //Stop identical M#Q"h5l
FileAccessI fileAccessI = null; //File Access interface wWSE[S$V
K3h"oVn
y\[q2M<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?b93! Q1
{ nB]mj_)R^
this.sURL = sURL; 87m`K Str7
this.nStartPos = nStart; Wtp=1
this.nEndPos = nEnd; #%L_wJB-
nThreadID = id; -B(p8YH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1QnaZhu'
} ):A.A,skf
O[z6W.
=kCiJ8q|
public void run() }^P"R[+4u
{ 2|U6dLZ!
while(nStartPos < nEndPos && !bStop) 3+q-yP#X
{ j8]M}Q$
P>$+XrTE
;jO+<~YP!
try{ |;^$IZSsz
URL url = new URL(sURL); "KSdC8MS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U??OiKVZ+
httpConnection.setRequestProperty("User-Agent","NetFox"); }SyK)W5Y
String sProperty = "bytes="+nStartPos+"-"; THB[(3q
httpConnection.setRequestProperty("RANGE",sProperty); zU!d(ge.E
Utility.log(sProperty); q8,,[R_
k~F,n
e2g`T{6M
InputStream input = httpConnection.getInputStream(); oel?we6
//logResponseHead(httpConnection); wDW/?lT&
M(uJ'Ud/!
73_-7'^mQ
byte[] b = new byte[1024]; ;e9&WEG_\
int nRead; +_QcLuV,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XQmg^x[,A
{ ZwiXeD+4
nStartPos += fileAccessI.write(b,0,nRead); <*P)"G
//if(nThreadID == 1) .ud&$-[a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xsNOjHk
} jj]|}G
G>jC+0nkry
q'IMt7}
Utility.log("Thread " + nThreadID + " is over!"); UPPlm\wb*
bDownOver = true; WP=uHg
//nPos = fileAccessI.write (b,0,nRead); ~PU}==*q
} kV8qpw}K
catch(Exception e){e.printStackTrace ();} _lRIS_^;eE
} hzpl;Mj
} (]10Z8"fJ
'(ZT}N
OYb:);o,iE
//打印回应的头信息 |`fuu2W!
public void logResponseHead(HttpURLConnection con) c0w1 N]+Ne
{ ps:E(\
for(int i=1;;i++) ?sR(
{ "9N;&^I
String header=con.getHeaderFieldKey(i); gA3f@7}d
if(header!=null) }]<|`FNc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @x;(yqOb
Utility.log(header+" : "+con.getHeaderField(header)); NS;LFeGD
else bfpoX,:
break; ':DL
} -.L )\
} FIu^Qd
a4Z e!l(
G]mD_J1$
public void splitterStop() ULs'oT)K;
{ "|R75m,Id
bStop = true; OI3j!L2f
} OKk"S_`
`DM)tm3&m
Y##lFEt
} Lf%}\0:
,4B8?0sH|
}r;=<mc,O
/* YN7`18u
**FileAccess.java )h{+pK
*//文件访问(定位，写) x|()f3{.
package NetFox; NJ;m&Tm,DF
import java.io.*; #.C2_MN>
)5y"T0]
NW*#./WdF8
public class FileAccessI implements Serializable{ #q-fRZ:P
Lr=^0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,}9 tJY@E
RandomAccessFile oSavedFile; 9}tl@
long nPos; 3\C+g{}e
]v?jfy
AS[j)x!
public FileAccessI() throws IOException CC3M7|eO3
{ \+0l#t$
this("",0); F[W0gjUc
} z+CX$.Z
<:mK&quf
<(yAat$H
public FileAccessI(String sName,long nPos) throws IOException Q("4R
{ wM3m'# xJ
oSavedFile = new RandomAccessFile(sName,"rw"); -lAY*2Jg
this.nPos = nPos; hTcU %Nc
oSavedFile.seek(nPos); 7r.~L
} t~44ub6GN`
L]&y[/\E1
;d_<6|*M
public synchronized int write(byte[] b,int nStart,int nLen) <=w!:
{ !4 lN[
int n = -1; yNU}1_oK
try{ {z;4t&5
oSavedFile.write(b,nStart,nLen); " SP6o
n = nLen; A..`?oGj
} 0;`+e22
catch(IOException e) Sq:J'%/z
{ wbh=v;
e.printStackTrace (); GaL UZviJ_
} 9\=SG"e(
cqW(9A|8
ZPz=\^
return n; NzeiGj
} 9wO2`e )
/NobS'd
fL]jk1.Xv-
} ]^i^L
%L wq.
'op_GW
/* ]<c\+9
**SiteInfoBean.java .~q>e*8AH
*/ /^bU8E&^M
package NetFox; W/~q%\M {
)UVekkq>Q
i->G{_gH
public class SiteInfoBean { !@y/{~Gu
[X8EfU}
#v9+9X`1L
private String sSiteURL; //Site's URL =qL^#h83y
private String sFilePath; //Saved File's Path 2~B5?(g
private String sFileName; //Saved File's Name qElPYN*wF
private int nSplitter; //Count of Splited Downloading File vL^ +X`.td
y=[{:
h(4\k?C5
public SiteInfoBean() jpoNTl'
{//nSplitter的缺省值为5 rls{~ZRl
//default value of nSplitter is 5 u]ps-R_$G
this("","","",5); XV`8Vb
} ;d]vAj
yF|+oTp
hJz]N$@W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OK47Q{.gh
{ $+Z2q<UT
sSiteURL= sURL; )e6sg]#
sFilePath = sPath; *~b~y7C
sFileName = sName; {MDM=;WP_
this.nSplitter = nSpiltter; +ef>ek
nNnfcA&W
`~41>mM%
} Ae"|a_>fMI
#uICHt3
|B64%w>Y
public String getSSiteURL() 036QV M$
{ bqx2lQf,_
return sSiteURL; HEhBOER?
} "QD>:G;u
'm-5
c"t&,OU:
public void setSSiteURL(String value) T1x67 b u
{ CJs ~!ww
sSiteURL = value; {G<1.
} bT|-G2g7Z
vGI)c&C>
=wD&hDn4
public String getSFilePath() yT='V1
{ >Ad`_g6Wew
return sFilePath; ,Ik~E&Ku2'
} `@vksjxu
[~`p~@\+
P4|A\|t
public void setSFilePath(String value) 141xi;o
{ bUSa#pNO>
sFilePath = value; W{j(=<|<
} K*4ib/'E a
Q:b0!
HNlW.y"
public String getSFileName() $'<$:;4b3
{ VRSBf;?
return sFileName; bMv[.Z@v(
} \%V !& !'
S?OCy4dk:
Z/4bxO=m
public void setSFileName(String value) "s(|pQh;
{ ~lqNWL^l
sFileName = value; j7NOYm5N
} Z J1@z.
!:tr\L {
I#7H)^us
public int getNSplitter() D-x*RRkpp
{ Ra:UnA
return nSplitter; vmo!
} ocp
`G:hC5B
t\Qm2Q)>
public void setNSplitter(int nCount) Vh]=sd<F
{ X gtn}7N.
nSplitter = nCount; L;+e)I]
} CUBL/U\=
} F6:LH,~8
2^:iU{
SxcE@WM
/* Rz6kwh=q
**Utility.java -@B6$XWL
*/ JRAU|gr
package NetFox; 4E1j0ARQQ
T eu.i
G9K& }_,
public class Utility { s*eM}d.p
")nKFs5
%/hokyx
public Utility() R$+"'N6p
{ 7vI ROK~
QXEZ?gx
6wXy;!2
} T]b&[?p|a[
uigzf^6,
//线程睡眠 #BZ5Mxzj
public static void sleep(int nSecond) G(t&(t`[
{ t~!ag#3['.
try{ wi[FBLB/8
Thread.sleep(nSecond); <dz_7hR"
} tq=M 9c
catch(Exception e) WE-+WC!!:
{ w7vQ6jkH
e.printStackTrace (); A.r.tf}:
} m2ph8KC
} O(_f&a
fWF!%|L
//日志 s!Iinc^p
public static void log(String sMsg) h///
{ Mt%Q5^
System.err.println(sMsg); I7t}$S6
} Lw?>1rTT/
o_[I#PT
yBv4 xKMH
public static void log(int sMsg) NL!xkcXO
{ 0TiDQ4}i[
System.err.println(sMsg); z:)*Aobwv
} 4FKgp|Y0
} `q1-yH0~4
yWr&G@>G
r"\<+$ 7
/* GW%!?mJ
**TestMethod.java *GdJ<B$
*/ %0 U@k!lP
package NetFox; l^$U~OB8k
M.C`nI4
zW.Ltz
public class TestMethod { y\dx \
&hZ6CV{
"39mhX2
public TestMethod() >km$zfM2-
{ ///xx/weblogic60b2_win.exe pNu?DF{ 3
try{ ,I,Zl.5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [g+WL\1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h_g"F@
SiteFileFetch fileFetch = new SiteFileFetch(bean); z@jKzyq
fileFetch.start(); m}6>F0Kv
} )_?HBTG
catch(Exception e){e.printStackTrace ();} UCo<ie\V
b8$%=Xp
1WY$Vs
} VwXR,(
'l-VWqR-
?4Rq +
public static void main(String[] args) {WeRFiQ?-
{ jX t5.9 t
new TestMethod(); \oP
} i9peQ61{
} +hlR
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