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)); ""a$[[ %WC
} 9Pe$}N
for(int i=0;i<nEndPos.length-1;i++) LlO8]b!P-^
{ @x+2b0 b
nEndPos = nStartPos[i+1]; j;Z?q%M{6
} T-6<qh
nEndPos[nEndPos.length-1] = nFileLength; m 0vW<
} 0FI |7
} -|KZOea
PBCGC^0{
ix4]^
//启动子线程 SnQT1U%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ybE2N
for(int i=0;i<nStartPos.length;i++) YnU)f@b#
{ pC>h"Hy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HdI)Z<Krp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9%iQ~
nStartPos,nEndPos,i); N\ !
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /}m*|cG/
fileSplitterFetch.start(); o!":mJy
} y7fy9jQ 8.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SnmUh~`L~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a~$Y;C_#<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bC1G5`v_D
nEndPos = " + nFileLength); z77>W}d
// fileSplitterFetch[nPos.length-1].start(); ~Q]5g7k=&
,Q7;(&x~
?V^7`3F
//等待子线程结束 qz>R"pj0g
//int count = 0; GgG#]a!_f
//是否结束while循环 pcwYgq#5
boolean breakWhile = false; uoI7' :Nv
+lqGf
pOo016afmA
while(!bStop) q -8G
{ *??lwvJp
write_nPos(); C\GP}:[T3
Utility.sleep(500); |50sGJE(
breakWhile = true; ([dd)QU
X$ZVY2
A!B.+p[G
for(int i=0;i<nStartPos.length;i++) 4v hz`1
{ u6ULk<<\
if(!fileSplitterFetch.bDownOver) ()?83Xj[c
{ LsuOmB|^
breakWhile = false; (jDz[b#OPz
break; }r5yAE
} MkPQ@so
} UE.kR+1
if(breakWhile) KaNs>[a8
break; ^x: lB>
C'#)mo_@t
Ct w<-'
//count++; UgC65O2
//if(count>4) \}?X5X>
// siteStop(); $0E+8xE
} }Pg}"fb^
m"iA#3l*=
nm,LKS7
System.err.println("文件下载结束！"); F^NK"<tW
} <]M.K3>
catch(Exception e){e.printStackTrace ();} Wjw,LwB
} aIV / c
- |g"q|
'%QCNO/
//获得文件长度 vyIH<@@p7
public long getFileSize() E>|X'I?r^
{ *(F`NJ 3
int nFileLength = -1; WYUDD_m
try{ mOsp~|d
URL url = new URL(siteInfoBean.getSSiteURL()); Ic0Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gVOAB-nw
httpConnection.setRequestProperty("User-Agent","NetFox"); 0<-E)\:[g
F+V!p4G
L>h8>JvQ
int responseCode=httpConnection.getResponseCode(); nTEN&8Y>R
if(responseCode>=400) Gs,:$Im
{ -V|"T+U
processErrorCode(responseCode); %'=*utOxy
return -2; //-2 represent access is error 0 Uropam
} o3fc-
"s(~k
:pqUUZ6x&
String sHeader; ,KW Q 6
@i1e0;\
&Vz$0{d5
for(int i=1;;i++) 3S:Lce'f
{ :hX[8u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qq| 5[I.?
//Utility.log(in.readLine()); ukW&\
sHeader=httpConnection.getHeaderFieldKey(i); FQDf?d5
if(sHeader!=null) [X.bR$>
{ }aVZ\PDg
if(sHeader.equals("Content-Length")) 3 !@
{ "d_wu#fO)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); YNEwX$)M,B
break; JNfL jfE)<
} ) CP
} cQU;PH]
else -Z"4W
break; N]A# ecm
} (jM0YtrD
} [>O!~
catch(IOException e){e.printStackTrace ();} CJ :V%|
catch(Exception e){e.printStackTrace ();} !qt2,V
Pb#M7=J/
g"!(@]L!@
Utility.log(nFileLength); "?I#!t%'
/o;M ?Nt6
t<!;shH,s
return nFileLength; j~Aq-8R=
} kOYUxr.b
w7V\_^&Id
7Q}pKq]P
//保存下载信息（文件指针位置） M3pE$KT0x
private void write_nPos() u5(8k_7
{ <xOX+D
try{ -zR<m
output = new DataOutputStream(new FileOutputStream(tmpFile)); +WH\,E
output.writeInt(nStartPos.length); &]nx^C8V;
for(int i=0;i<nStartPos.length;i++) %;,fI'M
{ ci~#G[_$S
// output.writeLong(nPos); =*2,^j
output.writeLong(fileSplitterFetch.nStartPos); _QPqF{iI
output.writeLong(fileSplitterFetch.nEndPos); @NiuT%#c
} \CL8~
output.close(); ANM#Kx+
} Ax;[Em?I
catch(IOException e){e.printStackTrace ();} 2%W;#oi?
catch(Exception e){e.printStackTrace ();} H3A$YkK [
} 2r, c{Ah@D
#Iw(+%D
$Habhw
//读取保存的下载信息（文件指针位置） jx: IK
private void read_nPos() q<JCgO-F<
{ $TI^8 3
try{ i+Z)`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~]?:v,UIm(
int nCount = input.readInt(); HN7CcE+l
nStartPos = new long[nCount]; !_S#8"
nEndPos = new long[nCount]; b3ohTmy4(
for(int i=0;i<nStartPos.length;i++) Hr|f(9xA
{ oP&/>GmXL
nStartPos = input.readLong(); x'GB#svi
nEndPos = input.readLong(); s2;~FK#/
} ge~@}&#iO@
input.close(); )^>LnQ_u
} U\KMeaF5e-
catch(IOException e){e.printStackTrace ();} [C'bfX5HB5
catch(Exception e){e.printStackTrace ();} 0a~t
} Hn|W3U
2HE@!*z9H
-'! J?~
private void processErrorCode(int nErrorCode) GWA"!~Hu
{ AI|vL4*Xd
System.err.println("Error Code : " + nErrorCode); "tJ+v*E
} k# [!; <
Nu5|tf9%A
oz)[-
//停止文件下载 I652Fcj
public void siteStop() ARKM[]
{ HBlk~eZ
bStop = true; cU1o$NRx
for(int i=0;i<nStartPos.length;i++) |5&+VI
fileSplitterFetch.splitterStop(); B `(jTL
_D '(R
{)[o*+9
} 5^B79A"}
} akj<*,
//负责部分文件的抓取 A;oHji#*
**FileSplitterFetch.java h0{X$&:
*/ VD;*UkapZx
package NetFox; g`Z=Y7jLH
$J[( 3
/9`4f"
import java.io.*; T &ZQie/
import java.net.*; &7L7|{18
XiUq#84Q
w,UE0i9I
public class FileSplitterFetch extends Thread { ~ao:9ynY
YpZB-9Krf
wlS/(:02
String sURL; //File URL )U/jD
long nStartPos; //File Snippet Start Position ]C_+u_9
long nEndPos; //File Snippet End Position (b&g4$!x&5
int nThreadID; //Thread's ID E C#0-,z
boolean bDownOver = false; //Downing is over ,f }$FZ
boolean bStop = false; //Stop identical Y|Iq~Qy~
FileAccessI fileAccessI = null; //File Access interface f ,F X# _4
[+ud7l
c%H' jB[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RSX27fb4
{ x#1Fi$.
this.sURL = sURL; D#;7S'C
this.nStartPos = nStart; 'eM0i[E+`
this.nEndPos = nEnd; ?qh-#,O9B
nThreadID = id; O?uICnmi6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X8C7d6ca
} NxP(&M(
t7=D$ua
fzsy<Vl",
public void run() e3I""D{)[=
{ 1J?v\S$ma`
while(nStartPos < nEndPos && !bStop) I G1];vX
{ =LW!$p
2 bc&sU)X
#QNN;&L]R
try{ (x=$b(I
URL url = new URL(sURL); f{BF%;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pMfb(D"
httpConnection.setRequestProperty("User-Agent","NetFox"); '|8dt "C
String sProperty = "bytes="+nStartPos+"-"; dNACE*g;q
httpConnection.setRequestProperty("RANGE",sProperty); '$ei3
Utility.log(sProperty); =oAS(7o
7=-Yxt
k{' ZaP)
InputStream input = httpConnection.getInputStream(); DDE-$)lf>
//logResponseHead(httpConnection); BP/nK.
O(^h_
-FZC|[is
byte[] b = new byte[1024]; C- .;m
int nRead; "\|P6H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0Lo8pe`DH
{ ]!/
nStartPos += fileAccessI.write(b,0,nRead); #p}GWS)
//if(nThreadID == 1) (< +A w7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H|%J"
} [.#nM
c'oiW)8;A
v[dUUR f
Utility.log("Thread " + nThreadID + " is over!"); 2B_|"J
bDownOver = true; <)7aNW.
//nPos = fileAccessI.write (b,0,nRead); nCQtn%j't
} 1wFu3fh@
catch(Exception e){e.printStackTrace ();} ]]j^
} <KMCNCU\+
} Iz0$T.T
gk6f_0?X'
Ht[$s40P
//打印回应的头信息 e=i X]%^
public void logResponseHead(HttpURLConnection con) "Zp&7hI
{ VLXA6+
for(int i=1;;i++) ocGrB)7eD
{ ~ZKJ:&f
String header=con.getHeaderFieldKey(i); Kg%9&l
if(header!=null) q5;dQ8Y?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x^ `/&+m
Utility.log(header+" : "+con.getHeaderField(header)); 1T!o`*
else ]8A*uyi
break; | 0
} g+#<;Gbpe
} oU\]#e^
?+zFa2J
Kd:l8%+
public void splitterStop() wgFX')l:
{ Q(& @ra!{
bStop = true; _vTr?jjfK
} {$8+n::
p/Pus;*s
$1.-m{Bd
} $hm[x$$
Bsa;,
Q.N!b7r7
/* vl:~&I&y;R
**FileAccess.java $_S-R 3L\
*//文件访问(定位，写) #Z1%XCt
package NetFox; 5]&sXs
import java.io.*; D!.c??
wV )\M]@
, >7PG2 a
public class FileAccessI implements Serializable{ MT!Y!*-5
"z9C@T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Sr \y1nt
RandomAccessFile oSavedFile; qA>#;UTp
long nPos; f1vD{M;
w[X-Q+7p(t
+jhzE%
public FileAccessI() throws IOException {0,b[
{ h*R@ d
this("",0); 8KJUC&`
} !q&Td
sU>IETo
c^I^jg2v
public FileAccessI(String sName,long nPos) throws IOException ==Egy:<:Q
{ -Cyo2wk
oSavedFile = new RandomAccessFile(sName,"rw"); rt^~ I\V
this.nPos = nPos; kWW2N0~$
oSavedFile.seek(nPos); LDQ,SS,
} yeiIP
CHGa_
fg LY{
public synchronized int write(byte[] b,int nStart,int nLen) PA'&]piPl:
{ Nvd(?+c
int n = -1; 5n?P}kca)
try{ ].s;Yxz
oSavedFile.write(b,nStart,nLen); x3i}IC
n = nLen; sT;wHtU
} JU17]gQ
catch(IOException e) j&X&&=
{ e*Wk;D&
e.printStackTrace (); X\`']\l
} pa46,q&M
5, $6mU#=
1 tOslP@
return n; OjhX:{"59
} Po58@g
l:'#pZ4T
:.5l
} m%6VwV7U
Z5Lmg
Fq~uuQ
/* 'S3<' X
**SiteInfoBean.java '^TeV=
*/ HThZ4Kg+
package NetFox; a U\|ZCH\]
s|WwBT
O&<p 8
public class SiteInfoBean { Dizz?O
OK]QDb
O2>c|=#
private String sSiteURL; //Site's URL I(^0/]'
private String sFilePath; //Saved File's Path ~5+RK16
private String sFileName; //Saved File's Name ?=9'?K/~a
private int nSplitter; //Count of Splited Downloading File {A/^;X{N^
"jAd.x?X7e
!hq2AY&H)
public SiteInfoBean() 5hmfdj6
{//nSplitter的缺省值为5 DURWE,W>
//default value of nSplitter is 5 :e7\z
this("","","",5); yU!1q}L!
} dCi:@+z8
Ysu\CZGX
[eD0L71[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >g<YH'U{
{ }T4|Kyu?
sSiteURL= sURL; s21} a,eB
sFilePath = sPath; *#YZm>h
sFileName = sName; qA GjR!=^
this.nSplitter = nSpiltter; D#LV&4e>.E
@#4-4.6I<x
y;ElSt;S
} J>
yIL=jzm`7
Fs~(>w@
public String getSSiteURL() nmU1xv_
{ -~{Z*1`,
return sSiteURL; 5z_d$.CIc
} 6|NH*#s
)bFl-
7Jlkn=9e:
public void setSSiteURL(String value) \o!3TK"N
{ OL 0YjU@
sSiteURL = value; -F7F 6!s
} +b-ON@9]J`
cp@Fj"
2Xl+}M.:Y
public String getSFilePath() j+h+Y|4J
{ V8/d27\
return sFilePath; -US:a8`
} zz*PAYl.
[8Pt$5]^
:dt[ #
public void setSFilePath(String value) _<c"/B
{ x1eC r_
sFilePath = value; (%fQhQ
} ]u5TvI,C
{\(G^B*\
QH-CZ6M
public String getSFileName() eJo" Z
{ {<ShUN
return sFileName; Rv&"h_"t
} jg?UwR&
4"2%mx:
bX$z)]KKu
public void setSFileName(String value) WRD z*Zf
{ Gk~aTO
sFileName = value; r)|~Rs!y,
} LWM<[8wJ4
ya&=UoI
WkuCnT
public int getNSplitter() jOV6%
{ sa8O<Ab
return nSplitter; n0=]C%wr
} &|XgWZS5
ATkd#k%S
nG'Yo8I^5
public void setNSplitter(int nCount) B!Wp=9)G
{ X)!XR/?
nSplitter = nCount; r^ Dm|^f#
} CC=I|/mBM
} >\1twd{u]
L"'=[O~
-4x! #|]
/* &`qYe)1Eo
**Utility.java TAUl{??,
*/ 4+hNP'e
package NetFox; FXr^ 4B}
^(TCUY~f&
J920A^)j!
public class Utility { 0HWSdf|w
KF'fg R
c$ /.Xp
public Utility() c \??kQH
{ yc*cT%?g
9CS"s_
*B3f ry
} ?c?@j}=?yY
qR.FjQOvn
//线程睡眠 C?|sQcCE
public static void sleep(int nSecond) }p?,J8=-
{ l?)>"^
try{ Wq3PN^
Thread.sleep(nSecond); h^(U:M=A
} 2-'_Nwkl*
catch(Exception e) >IS4
{ _-vlN
e.printStackTrace (); ;:=j{,&dl[
} _AF$E"f@
} a>vxox) %
2e\"?yOD
//日志 Yuv=<V
public static void log(String sMsg) &n| <NF
{ |y7TYjg6
System.err.println(sMsg); M<Bo<,!ua
} n*9QSyJN]
S!A:/(^WB
fL|9/sojz
public static void log(int sMsg) yr+QV:oVA
{ zmQQ/7K
System.err.println(sMsg); 8(n>99VVK
} 'ij+MU1
} ,IhQ%)l
cy@oAoBq
)$p36dWl
/* 3_@IE2dA
**TestMethod.java Y"t|0dO%b
*/ /HUT6B
package NetFox; 2(!W 9#]
iY`[dsT
}N9PV/a
public class TestMethod { %S^ke`MhF
5:38}p9`
pImq<Z
public TestMethod() $E[O}+L$#
{ ///xx/weblogic60b2_win.exe O_ r-(wE4
try{ I0l3"5X a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @8c@H#H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r } Wdj
SiteFileFetch fileFetch = new SiteFileFetch(bean); cl`kd)"v
fileFetch.start(); /mJb$5=1
} r2f%E:-0G
catch(Exception e){e.printStackTrace ();} JVg}XwR
#.u&2eyqQ
{KSLB8gtL
} roZn{+f
f]10^y5&
yx#!2Z0hw
public static void main(String[] args) }{:Jj/d p
{ .Od@i$E>&
new TestMethod(); E<LH-_$
} V?t*c [
} &u9,|n]O9
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