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)); rV%T+!n%c
} r3g^0|)
for(int i=0;i<nEndPos.length-1;i++) Ia#!T"]@W6
{ `w:kY9
nEndPos = nStartPos[i+1]; I!Z`'1"
} 3tTOs
nEndPos[nEndPos.length-1] = nFileLength; z:#]P0
} CLaQE{
} .u&xo{$'dS
(O0Ry2uk
|z=`Ur@)
//启动子线程 ct3i^,i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AuXUD9-
for(int i=0;i<nStartPos.length;i++) z.cDbkf}
{ H1kI+YJ@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B&a{,.m&q6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,w#lUgp
nStartPos,nEndPos,i); xOe1v9<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'OtTq8G
fileSplitterFetch.start(); /@ @F nQ++
} G)?*BH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J.1c,@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R xITMt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \yJ 4+vo2Q
nEndPos = " + nFileLength); DPzW,aIgv
// fileSplitterFetch[nPos.length-1].start(); )sm9%|.&
hc|A:v)]
NlEyT9
//等待子线程结束 OOSf<I*>
//int count = 0; eA!Z7 '
//是否结束while循环 %_Vz0 D!7
boolean breakWhile = false; _K#7#qp2
K7&]|^M9
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while(!bStop) 6h/!,j0:t_
{ ^ZsIQ4@`
write_nPos(); F[\T'{
Utility.sleep(500); t_Eivm-,B
breakWhile = true; js"Yh
J0IKI,X.
_W(xO |,M
for(int i=0;i<nStartPos.length;i++) R WY>`.su
{ Bdh*[S\u@E
if(!fileSplitterFetch.bDownOver) -4QZ/*
{ LkJq Bg
breakWhile = false; 85# 3|5n
break; -`q!mdA2
} LBG`DYR@
} l^R:W#*+U
if(breakWhile) &;ddnxFI
break; zKP[]S-
]CP5s5
A/=cGE
//count++; 6g-jhsW6
//if(count>4) P7}w^#x
// siteStop(); w-WAgAch
} k`>qb8,
&k)+]r
3)VO{Cj!
System.err.println("文件下载结束！"); -aJ(-Np$f
} 49E| f ^q
catch(Exception e){e.printStackTrace ();} {@KLN<
} ruagJS)+
kVtP~
*P *.'XM
//获得文件长度 :c]y/lQmV
public long getFileSize() g[i;>XyP
{ 3\ajnd|
int nFileLength = -1; %rs2{Q2k
try{ uvl91~&G
URL url = new URL(siteInfoBean.getSSiteURL()); fAStM:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S3x^#83
httpConnection.setRequestProperty("User-Agent","NetFox"); *}:P
PYQ
VT>-*
int responseCode=httpConnection.getResponseCode(); d >L8SL
if(responseCode>=400) FsUH/Y y
{ P:6K
processErrorCode(responseCode); jR1^e$
return -2; //-2 represent access is error Nkb%4ofKqu
} >%6j-:S
# d"M(nt
0 F8xS8vK+
String sHeader; kN 2mPD/
<*iFVjSI(
hlyh8=Z6o
for(int i=1;;i++) LGy62 y$
{ 0e>?!Z E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >}.~Y#Ge
//Utility.log(in.readLine()); OtL~NTY
sHeader=httpConnection.getHeaderFieldKey(i); <2j$P Y9
if(sHeader!=null) b^i$2$9_
{ nS$4[!0
if(sHeader.equals("Content-Length")) TS=%iMa
{ 5D3&E_S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ce4rhtkV
break; uF%N`e^S
} Nc6y]eGz
} *C)m#[#:u
else or ~@!
break; 7g8\q@',
} im>/$!&OyI
} `o_i+?E
catch(IOException e){e.printStackTrace ();} i]zh8|">
catch(Exception e){e.printStackTrace ();} g0~m[[
([JFX@
3mE8tTA$R
Utility.log(nFileLength); 8fvKVS
2hntQ1[
tF*Sg{:bCa
return nFileLength; #@Tm5z
} MAqETjB
1jSmTI d
L) _ VdB
//保存下载信息（文件指针位置） eG1A7n'6W
private void write_nPos() YedF%
{ LfnQcI$kO
try{ /;TD n>lq
output = new DataOutputStream(new FileOutputStream(tmpFile)); /jaO\t'q
output.writeInt(nStartPos.length); VKXB)-'L
for(int i=0;i<nStartPos.length;i++) L(y~ ,Kc
{ r+]a
// output.writeLong(nPos); Qc9[/4R>
output.writeLong(fileSplitterFetch.nStartPos); mV7_O//
output.writeLong(fileSplitterFetch.nEndPos); |[V6R\l39
} wc6#C>=F
output.close(); UHl1>(U
} UWCm:eRQ
catch(IOException e){e.printStackTrace ();} *}r6V"pH~
catch(Exception e){e.printStackTrace ();} 5U_ar
} `ER#S_}
kyB>]2
T/L\|_:'
//读取保存的下载信息（文件指针位置） ^y&2N
private void read_nPos() kYS\TMt,C
{ u8~5e
try{ l9rN!Q|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >Y3zO2Cr
int nCount = input.readInt(); z1e+Ob&
nStartPos = new long[nCount]; a<pEVV\NB~
nEndPos = new long[nCount]; A[88IMZs
for(int i=0;i<nStartPos.length;i++) GO#eI]>/r
{ g[{rX4~|
nStartPos = input.readLong(); sQzr+]+#9
nEndPos = input.readLong(); CwEb ?
} yK2>ou
input.close(); sYTToanA$?
} 78mJ3/?rC
catch(IOException e){e.printStackTrace ();} FP6JfI8
catch(Exception e){e.printStackTrace ();} fb]=MoiJ
} 7z&^i-l.
)6he;+
w/0;N`YB
private void processErrorCode(int nErrorCode) 9Xh<vh8&
{ ,(yaWd6
System.err.println("Error Code : " + nErrorCode); ]G~u8HPH!m
} j1@PfKh
FZ% WD@=
MIv,$
//停止文件下载 1N8YD .3
public void siteStop() :rmi8!o
{ _ZuI x=!
bStop = true; zy9W{{:P(1
for(int i=0;i<nStartPos.length;i++) GsWf$/iC:
fileSplitterFetch.splitterStop(); BI6`@}%7>
na/,1iI<
7 (i\?
} n22OPvp
} Yceex}X*5
//负责部分文件的抓取 x A ZRl
**FileSplitterFetch.java WoMMAo~
*/ 0[OlJMVf
package NetFox; ) nnv{hN
}Tk*?tYt
|i'w"Tz4
import java.io.*; k*T&>$k}^
import java.net.*; "CT`]:GGK
^W,x
kh*td(pfP9
public class FileSplitterFetch extends Thread { FwSV \N+#'
QtqE&j
2Y9@[
String sURL; //File URL gG6BEsGa,
long nStartPos; //File Snippet Start Position BG@[m
long nEndPos; //File Snippet End Position -Ly A
int nThreadID; //Thread's ID EG!):P
boolean bDownOver = false; //Downing is over 771r(X?Fa
boolean bStop = false; //Stop identical E'_$?wWn5
FileAccessI fileAccessI = null; //File Access interface .`N&,&H
I* JSb9r
q}7(w$&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fL R.2vJ
{ U[l{cRT
this.sURL = sURL; 7vsXfIP+
this.nStartPos = nStart; {cYbM[}U"
this.nEndPos = nEnd; BO=j*.YKy
nThreadID = id; :sb+jk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u!VY6y7p
} ;hU~nj+{
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Q-S5("
public void run() /T/7O
{ h|&qWv
while(nStartPos < nEndPos && !bStop) so\8.(7n
{ X1~ B
!p"Ijz5
{nmBIk2v
try{ x\XOtjJr
URL url = new URL(sURL); 0Z~G:$O/i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y <21~g=
httpConnection.setRequestProperty("User-Agent","NetFox"); EY 9N{
String sProperty = "bytes="+nStartPos+"-"; ,1-#Z"~c
httpConnection.setRequestProperty("RANGE",sProperty); SSI('6Z/
Utility.log(sProperty); #kDJ>r |&-
~Aq$GH4
<)9E.h
InputStream input = httpConnection.getInputStream(); +LAjh)m
//logResponseHead(httpConnection); ?f[U8S}
nHi6$} I
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byte[] b = new byte[1024]; *+'l|VaVq\
int nRead; .1& F p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0(dXU\Y
{ 5l(Q#pSX
nStartPos += fileAccessI.write(b,0,nRead); ) bGzsb1\
//if(nThreadID == 1) 5;-?qcb^w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lv?e[GA
} )OcG$H NK
*l4`2eqZ
Kf7v_T/
Utility.log("Thread " + nThreadID + " is over!"); ~/kx
bDownOver = true; -J=N
//nPos = fileAccessI.write (b,0,nRead); rn8t<=ptH3
} #>\+6W17U
catch(Exception e){e.printStackTrace ();} v5o@ls
} 86\B|!
} Arb-,[kwN
KFMEY\6\h
CK+_T}+-
//打印回应的头信息 m`lsUN,
public void logResponseHead(HttpURLConnection con) (t)a u
{ BAS3&fA
for(int i=1;;i++) {n>W8sN<
{ pI|H9
String header=con.getHeaderFieldKey(i); BWN[>H %S
if(header!=null) S7 Tem:/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2r=A'
Utility.log(header+" : "+con.getHeaderField(header)); v'zf*]9
else 55T c
break; c,I|O' &k
} cU'^ Ja?%
} :X6A9jmd
_n+./B
#e8NF,H5
public void splitterStop() KzC`*U[
{ ;ywQk| r
bStop = true; 7o]p0iLej
} /P/S0
Ug^v ]B9
"xV9$m>
} &N!;d E
[!E8C9Q#!
LMvsYc~]q
/* yXx}'=&!0
**FileAccess.java G_] (7
*//文件访问(定位，写) E|Lv_4lb=
package NetFox; to
import java.io.*; 'j+J?Y^
A"@C }f
8HyK;+ZkVd
public class FileAccessI implements Serializable{ Sgt@G=_o
.{1MM8 Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 PiRbdl
RandomAccessFile oSavedFile; f`jRLo*L
long nPos; Nz&J&\X)tD
?N|B,F
i}5 #n
public FileAccessI() throws IOException f}'E|:Z 7k
{ H[{ch t h
this("",0); <eq93
} IRZ?'Im
;?9u#FRtw
S/ Y1NH
public FileAccessI(String sName,long nPos) throws IOException hD>O LoO
{ N*Owfr1N
oSavedFile = new RandomAccessFile(sName,"rw"); ;Vad| -
this.nPos = nPos; K6.*)7$#
oSavedFile.seek(nPos); ;,y9
} zA![c l>$
@])qw_
0FHX
public synchronized int write(byte[] b,int nStart,int nLen) ba3_55]
{ $e! i4pM
int n = -1; k.DDfuKN
try{ uSs~P%@6|
oSavedFile.write(b,nStart,nLen); GJA3
n = nLen; ,OLN%2Sq
} S)[`Bm
catch(IOException e) H!ZPP8]j>
{ or u.a
e.printStackTrace (); ESZ6<!S
} EV@xUq!x.
V$wf;v0d(
?.:C+*+
return n; bQ=R,
} 1_7}B4
<8Qa"<4f;
MdWT[
} 0j1I
FxC@KZG
_wg6}3
/* LmLV2f
**SiteInfoBean.java @>J4K#"
*/ ?<Dinq
package NetFox; Rp)82- .
m&OzT~?_>N
IN!m
public class SiteInfoBean { M[0@3"}}
w*ig[{ I
Got5(^'c
private String sSiteURL; //Site's URL V&DS+'P
private String sFilePath; //Saved File's Path oSt-w{!
private String sFileName; //Saved File's Name P'Jw:)k(
private int nSplitter; //Count of Splited Downloading File .3,s4\.kT
JQ%`]=n(/
iuq-M?1
public SiteInfoBean() Od'!v&
{//nSplitter的缺省值为5 ?0+D1w
//default value of nSplitter is 5 er}/~@JJ
this("","","",5); 1dOVH7
} 4ow)vS(
"qb3\0O
)L`0VTw'M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 16o3ER
{ z@cL<.0CE
sSiteURL= sURL; &gkloP@
sFilePath = sPath; pd,5.d
sFileName = sName; kzGD*
this.nSplitter = nSpiltter; fAfsKO*
Fk>/
UR?[ba_h
} iwL\Ha
a[)in ,3
'u$$scGt
public String getSSiteURL() l?B\TA^
{ lC.Yu$O5
return sSiteURL; @Q3aJ98)2
} g^1M]1.f
<?,o {
;*+jCL2F
public void setSSiteURL(String value) {y'c*NS
{ mz[rB|v"/7
sSiteURL = value; w/N.#s^
} G;FY2;adK
q?&vV`PG5
Tm@mk
public String getSFilePath() y&A*/J4P
{ .8l\;/o|
return sFilePath; \Btv76*,
} 4_`+&
ycRy!0l
dV8mI,h
public void setSFilePath(String value) qr(SAIX"
{ <O>r e3s
sFilePath = value; N>7INK
} BULX*eOt
) ]U-7
/_?Ly$>'
public String getSFileName() 6Ez}A|i
{ ge[f/"u
return sFileName; Q,Hw@w<1
} mT>56\63
x9~d_>'A
7f'9Dm`
public void setSFileName(String value) 4)-LlYS_d<
{ sn/^#Aa=N
sFileName = value; _{KQQ5k\
} g%#" 5Kr
!SD?
>.SU=HG;
public int getNSplitter() 1/3Go97/qV
{ B+wSLi(
return nSplitter; Io{)@H"f
} .3A66 O~zT
I' ej?~
a84^"GH7
public void setNSplitter(int nCount) b|wCR%
{ "Nn/vid;
nSplitter = nCount; 9n$GeRO
} %?y ?rt
} & p"ks8"
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4_8%ZaQ\.?
/* a [iC!F2
**Utility.java Jt.dR6,
*/ *n N;!*J
package NetFox; oJUVW"X6
"44VvpQC
0ho+Y@8
public class Utility { ,;'9PsIS^
v}IkY
ngcXS2S_
public Utility() $OHY^IE(
{ #]oVVf_
YL=?Nk/
AM1J ^Dp
} "6lf~%R"
OA_:_%a(
//线程睡眠 LXG,IG
public static void sleep(int nSecond) amK?LDf]
{ Ajr]&H4
try{ ce/Rzid
Thread.sleep(nSecond); bPAp0}{Fu
} :O{`!&[>L
catch(Exception e) cnXIE{9M
{ Fa,a)JY>
e.printStackTrace (); 9Y- Sqk+
} mrX3/e
} Di<KRg1W]}
s@E"EWp0
//日志 X5cl'J(j9
public static void log(String sMsg) bBc<yaN
{ 0R>M_|
System.err.println(sMsg); F"#bCnS
} fKf5i@CvB@
G\?fWqx
Y5$5qQ
public static void log(int sMsg) j08}5Eo
{ 0"(5\T
System.err.println(sMsg); I&U?8
} KtUI(*$`
} YBN@{P$
_p\
qgvg MWj
/* }a,j1r_Hl&
**TestMethod.java Vz!W(+
*/ !krbGpTVH
package NetFox; ce\]o^4
z*.4Y
#Sr_PEo _
public class TestMethod { -LJbx<'
I#zrz3WU
%kS+n_*
public TestMethod() U,yU-8z/
{ ///xx/weblogic60b2_win.exe \]e"#"v}}_
try{ 2K'3ry)[y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~&4Hc%*IB
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qYBoo]}a
SiteFileFetch fileFetch = new SiteFileFetch(bean); f ."bq43(
fileFetch.start(); ~C6d5\
} ?1K|.lr
catch(Exception e){e.printStackTrace ();} 3xWeN#T0
%<CahzYc6
Wp`wIe6
} _(&^M[O
QU_O9 BN
jxU1u"WU
public static void main(String[] args) %Wkvo-rOq
{ ;t{Ew+s
new TestMethod(); dFFJw[$8w
} E%t_17,=j
} im_WTZz2P
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