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)); 3j{VpacZY
} 9fk@C/$
for(int i=0;i<nEndPos.length-1;i++) #[.vfG
{ 'qGKS:8
nEndPos = nStartPos[i+1]; w]Q0}Z
} czMu<@c [
nEndPos[nEndPos.length-1] = nFileLength; $"P9I-\m
} x/nlIoT
} f1cQ*#2~
U) tqo_
g+5{&YD
//启动子线程 4@,d{qp~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y{].%xM5
for(int i=0;i<nStartPos.length;i++) {`Ekv/XWa
{ em^|E73
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pdcP;.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H*#L~!]
nStartPos,nEndPos,i); Ri$wt.b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qo*,2B9R L
fileSplitterFetch.start(); BMw_F)hTO
} ]+1?T)<!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6S-1Wc4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X#l]%IrW!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T6s~f$G
nEndPos = " + nFileLength); Q'f!392|
// fileSplitterFetch[nPos.length-1].start(); 1WGcv O)<
kcy?;b;z
&^ECQ
//等待子线程结束 ^;J@]&[ ~
//int count = 0; l0cws`V
//是否结束while循环 3"28=)o
boolean breakWhile = false; @@L@r6
(p1y/"Xh
ahagt9[,:F
while(!bStop) (!h%) _?.l
{ &!I^m
write_nPos(); xkv2#"*v
Utility.sleep(500); wJ_E\vP
breakWhile = true; {}Y QB'}
SHw%u~[hu
>>lT-w
for(int i=0;i<nStartPos.length;i++) hg}Rh
{ FhJ8}at+e
if(!fileSplitterFetch.bDownOver) l26DPtWi
{ jM%qv
breakWhile = false; Cm:&n|
break; lO482l_t
} p5<2tSD
} (2He]M\
if(breakWhile) fH_G;#q
break; (mq 7{;7y
JpVV0x/Q/_
2ql7*g?Uq@
//count++; B_FfXFQm<
//if(count>4) f =H,BQ
// siteStop(); z7+y{-{Z
} ([loWr}QR
!!Tk'=t9"3
0 S3~IeJ
System.err.println("文件下载结束！"); Ndj9B|s_
} \>0F{-cR$
catch(Exception e){e.printStackTrace ();} pg3B^
} S>~QuCMY
".&x`C
vkE[Ur>
//获得文件长度 3zJbb3e
public long getFileSize() ZN)a}\]
{ %G9:M;|'
int nFileLength = -1; =>ooB/
try{ F(E3U'G
URL url = new URL(siteInfoBean.getSSiteURL()); r!eCfV7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9moenkL
httpConnection.setRequestProperty("User-Agent","NetFox"); }8E//$J
?}*A/-Hx0U
'T54k
int responseCode=httpConnection.getResponseCode(); Y21,!$4gb
if(responseCode>=400) sY?pp '}a
{ owA3>E5t&
processErrorCode(responseCode); ZoJ:4uo N`
return -2; //-2 represent access is error fo])=KM
} g`KVF"8
Lu&2^USTO
&wj;:f
String sHeader; ,RFcR[ak
Zf<M14iM
wAE,mw
for(int i=1;;i++) m ys5B}
{ =re1xR!E5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YH`/;H=$G/
//Utility.log(in.readLine()); \LB =_W$
sHeader=httpConnection.getHeaderFieldKey(i); nVI\Or[
if(sHeader!=null) XZhX%OT!
{ <\k=j{@
if(sHeader.equals("Content-Length")) \M>+6m@w
{ ]}Hcb)'j@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6T 2jVNg
break; Fy-+? ~
} 6,'v /A-
} ehO@3%z30c
else O~F/pJN`
break; ;u LD_1%
} 'tK5s>gv<
} se](hu~w
catch(IOException e){e.printStackTrace ();} ;czMsHu0X
catch(Exception e){e.printStackTrace ();} iqCKVo7:M
hx$-d}W{
Qg+0(odd
Utility.log(nFileLength); )%8oE3O#
VXvr`U\
;i`X&[y;
return nFileLength; N7j
} VHX&#vm*
BsVUEF,N
"m3:HS
//保存下载信息（文件指针位置） ShanwaCDqv
private void write_nPos() nf!RB-orF
{ Y>-|`2Z
try{ po_||NIY
output = new DataOutputStream(new FileOutputStream(tmpFile)); =%AFn9q
output.writeInt(nStartPos.length); 0 1[LPN
for(int i=0;i<nStartPos.length;i++) _xign 3
{ #ej^K |Qx
// output.writeLong(nPos); FKflN
output.writeLong(fileSplitterFetch.nStartPos); yn<z!z%mz
output.writeLong(fileSplitterFetch.nEndPos); H<|I&nV
} eW)(u$C|qL
output.close(); KU[eY}
} 6~\z]LZ
catch(IOException e){e.printStackTrace ();} uf,4GPo,
catch(Exception e){e.printStackTrace ();} N$J)Ow
} T{u!4Yu
wL,b.]
}*l V
//读取保存的下载信息（文件指针位置） ~I6Er6$C^
private void read_nPos() >jAr9Blz]
{ )F 6#n&2
try{ N m-{$U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); VY8p[`
int nCount = input.readInt(); z^9Yoqog
nStartPos = new long[nCount]; MJ[#Gq\0R
nEndPos = new long[nCount]; th8f
for(int i=0;i<nStartPos.length;i++) P%>? O :a
{ 4R\bU"+jZ_
nStartPos = input.readLong(); V#!ihL/>
nEndPos = input.readLong(); xd8UdQ,lt
} =9n$at$l@
input.close(); &9\z!r6mc
} "/hM&
catch(IOException e){e.printStackTrace ();} i%H_ua
catch(Exception e){e.printStackTrace ();} E!'H,#"P
} J) v~
_#9:cH*
VP=(",`
private void processErrorCode(int nErrorCode) |jm|/{lc
{ <Fb3\T L
System.err.println("Error Code : " + nErrorCode); 70&v`"
} 13Ga #
5gW`;Cdbyc
hb9X<N+p
//停止文件下载 c+AZ(6O?\
public void siteStop() 1(M0C[P
{ 8Q^yh6z
bStop = true; }[Uh4k8P
for(int i=0;i<nStartPos.length;i++) CFqoD l
fileSplitterFetch.splitterStop(); -yeQQ4b
0m,A`*o
TCp!4-~,
} 49}yw3-
} Pgg6(O9}B^
//负责部分文件的抓取 c"t1E-Nsk
**FileSplitterFetch.java 4vTO #F
*/ ` =dD6r
package NetFox; PaV[{CD
&oiX/UaY
gs 8w/
import java.io.*; rq9{m(
import java.net.*; MK[l*=\s
:N^1T6v
Ken|!rL
public class FileSplitterFetch extends Thread { 4cL NPl<
Mm-FdP m
:SG9ygq'
String sURL; //File URL 6BVV2j)zl:
long nStartPos; //File Snippet Start Position .%`|vGF
long nEndPos; //File Snippet End Position )7=B]{B_
int nThreadID; //Thread's ID Y+<C[Fiq
boolean bDownOver = false; //Downing is over (w]w 2&YD
boolean bStop = false; //Stop identical FQB)rxP
FileAccessI fileAccessI = null; //File Access interface BDxrSq,H
:gY$/1SYD
C<fWDLwYqV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lO8.Q"mxo
{ F1R91V|
this.sURL = sURL; 5/DTE:M<
this.nStartPos = nStart; _3tHzDSG#
this.nEndPos = nEnd; m3 ;
nThreadID = id; wq_c^Ioy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @8Drhx
} (p`'Okw
C=@BkneQ
v83uGEq(
public void run() shxr^
{ IGT~@);
while(nStartPos < nEndPos && !bStop) (}O)pqZ>
{ a*CP1@O
3/:O8H
0~A<AF*t
try{ UA{sUj+?
URL url = new URL(sURL); Nv*x^y]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >OE.6)'Rm
httpConnection.setRequestProperty("User-Agent","NetFox"); [Z,AquCU(
String sProperty = "bytes="+nStartPos+"-"; u_@%}zo?5*
httpConnection.setRequestProperty("RANGE",sProperty); yk#yrxM
Utility.log(sProperty); qyUcjc%[
lf0/0KH
Vv' e,m
InputStream input = httpConnection.getInputStream(); mW1Sd#0
//logResponseHead(httpConnection); PTA;a0A
n)} J<
y4,2Xs9,
byte[] b = new byte[1024]; >NB}Bc
int nRead; J:f>/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {d}-SoxH
{ I"Ji_4QV
nStartPos += fileAccessI.write(b,0,nRead); /`hr)
//if(nThreadID == 1) ' F`*(\#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 84b;G4K
} 3{Ze>yFE
NUH;GMj,,
Y::fcMJr;Q
Utility.log("Thread " + nThreadID + " is over!"); ,TOLr%+v~n
bDownOver = true; ) EEr?"
//nPos = fileAccessI.write (b,0,nRead); 7t5X
} %2BFbaE
catch(Exception e){e.printStackTrace ();} yZK1bnYG|I
} k(=\&T
} @5 kKMz
Yp 6;Y7^
:m5& i&
//打印回应的头信息 )oTEB#J
public void logResponseHead(HttpURLConnection con) Qat%<;P2
{ FvG9PPd
for(int i=1;;i++) }yx{13:[
{ 2-llT
String header=con.getHeaderFieldKey(i); n8[sR;r5f
if(header!=null) |rdG+>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &-<"HW
Utility.log(header+" : "+con.getHeaderField(header)); wuzz Wq
else ?#}=!$p
break; :m8ED[9b
} ||`w MWq
} n#z^uq|v
|GK [I
^eM=h
public void splitterStop() 1GOa'bxm
{ lx$Y-Tb^F
bStop = true; \^Y#"zXo1
} Ep5lmzg
vlyq2>TfR
(n" )
} 8o-?Y.2
]~WP;o
:m#vvH
/* vR,HCI
**FileAccess.java hp-<8Mf
*//文件访问(定位，写) ,z1# |Y
package NetFox; n/$BdFH
import java.io.*; C^nL{ZP,
G8u8&|
e"r}I!.
public class FileAccessI implements Serializable{ /lr RbZ
KG>.7xVWV7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 + W@r p#
RandomAccessFile oSavedFile; Z6D4VZVF
long nPos; ^{6Y7T]
FT|*~_@
iM8hGQ`
public FileAccessI() throws IOException zNE!m:s
{ yqejd_cd
this("",0); *N>Qj-KAM_
} =7e8N&-nv
^]U2Jd
!-N!80
public FileAccessI(String sName,long nPos) throws IOException iS=T/<|?
{ 30DpIkf
oSavedFile = new RandomAccessFile(sName,"rw"); /;OJ=x3i
this.nPos = nPos; N"r ;d+LTL
oSavedFile.seek(nPos); _'I9rGlx3
} '')G6-c/
H~ks"D1
M<ad>M
public synchronized int write(byte[] b,int nStart,int nLen) l$zNsf.
{ ,1~Zqprn
int n = -1; //J:p,AF
try{ o8s&n3mY}y
oSavedFile.write(b,nStart,nLen); `4k;`a
n = nLen; s{s0#g
} U">OdoZ,E+
catch(IOException e) dtF6IdAf
{ @%#(Hse
e.printStackTrace (); kk~{2
} Lvp/} /H/
dtg Ja_
PU'v o4
return n; OW-+23)sj
} F)gL=6h
Qb(CH
Fn[~5/
} qb"!
`Mjm/9+18
Rp@u.C<
/* htF&VeIte
**SiteInfoBean.java (vI7qD_
*/ Ce0I8B2y
package NetFox; I* bjE'
61mQJHl.
N$y4>g
public class SiteInfoBean { >#q|Pjv]
~(Tz <
S;t~"87v*
private String sSiteURL; //Site's URL +?.,pqn<=
private String sFilePath; //Saved File's Path F;b|A`M
private String sFileName; //Saved File's Name mdZELRu
private int nSplitter; //Count of Splited Downloading File qnA:[H;F
#-@{rgH
;8T<L[ ^U
public SiteInfoBean() .1pEq~>
{//nSplitter的缺省值为5 yr=r?h}
//default value of nSplitter is 5 VKs\b-1
this("","","",5); JBwTmOvQ
} =?f}h{8x>
{[s<\<~B*
nuCK7X
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V`H#|8\i
{ {$EXI]f
sSiteURL= sURL; I}q-J~s
sFilePath = sPath; #E ~FF@a
sFileName = sName; m_Rgv.gE^
this.nSplitter = nSpiltter; R80R{Ze
y&CUT:M6
9.@(&
} fC-^[Af)
p;5WLAF
b9YpUm7#
public String getSSiteURL() +p[~hM6?
{ =CVw0'yZ
return sSiteURL; ko:I.6-K
} va<+)b\
$`oA$E3
?UxY4m%R;
public void setSSiteURL(String value) cpy"1=K~M
{ 3Yf$WE8#l
sSiteURL = value; gON6jnDO
} {c1qC zM4
|`okIqp
4ku/3/6
public String getSFilePath() ex=~l O
{ =aekY;/
return sFilePath; [_0g^(`
} j~{2fd<>
i f"v4PHq
\%C[l
public void setSFilePath(String value) yjr@v!o
{ m3WV<Cbz
sFilePath = value; w\mF2h
} N<{`n;
BmM,vllO
aE%VH ;?
public String getSFileName() H|Nw)*.
{ "5YdmBy
return sFileName; LBE".+
} k|_2aQ02
"4`%NA
<oO,CXF
public void setSFileName(String value) G<z)Ydh_
{ C1/jA>XW
sFileName = value; O<3,n;56Z
} n=&c5!
5;{Bdvcv
nT12[@:Tr
public int getNSplitter() r#Mx~Zg~
{ W<4\4
return nSplitter; 42u\Y_^ID
} md`ToU
]/bE${W*]
i#lo?\PO>
public void setNSplitter(int nCount) ypd?mw&1}
{ 4yA`);r62
nSplitter = nCount; F[u%t34'
} p4t)Z#0
} sfV.X:ev
=l(JJ
m@@QT<
/* HFr3(gNj@
**Utility.java Wy4^mOv
*/ >S!DIL
package NetFox; E1C_d'
NM@An2
) b10%n^
public class Utility { <C77_t
f*],j
(HI%C@e9
public Utility() _Pkh`}W:
{ p5l$On
?a%i|Z7!
4I*Mc%dD
} Q.1ohj0)
s]c$]&IGG
//线程睡眠 &[RU.Q!_H
public static void sleep(int nSecond) q?L(V+X
{ _);Kb/
try{ ?~.&Y
Thread.sleep(nSecond); {wP|b@(1t
} hBhkb ~Oky
catch(Exception e) 6\;1<Sw*
{ ra>`J_
e.printStackTrace (); )0mDN.
} ?U08A{ c
} 1VFqT'
pCc7T-"og
//日志 %B*dj9n^q
public static void log(String sMsg) 9C;Y5E~'L
{ 3(+#^aw
System.err.println(sMsg); r%pFq1/'!
} 6t:c]G'J
'I]"=O,
YZRB4T9
public static void log(int sMsg) wF8\
{ j\f$r,4
System.err.println(sMsg); *]WXM.R8
} LFyceFbm
} l7,qWSsnK
Zk UuniO
uR@`T18
/* Qiw4'xQm
**TestMethod.java 7[BL 1HI*
*/ |nN/x<v
package NetFox; io7U[#
C-u/{CP
Ok&>[qu
public class TestMethod { ^~qs-.?
%uVJLz
Lc<xgN+cJ
public TestMethod() /dt!J `:
{ ///xx/weblogic60b2_win.exe L59oh
try{ 2?iOB6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _M[[vXH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WgJAr73 l
SiteFileFetch fileFetch = new SiteFileFetch(bean); !`[I>:Ex
fileFetch.start(); 8 QF?W{NK
} \.P}`Bpa
catch(Exception e){e.printStackTrace ();} G*i#\
5jV97x)BGx
:IVMTdYf
} o?K|[gNi
6bKO;^0
DhNo +"!z
public static void main(String[] args) Nu/Qa:H_{
{ |8 2tw|<o
new TestMethod(); >B/&V|E
} jne9=Als5
} 1{x~iZa
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