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)); |#i|BVnoE
} <>71;%e;'
for(int i=0;i<nEndPos.length-1;i++) +eUWf{(_
{ i8nzPKF2$3
nEndPos = nStartPos[i+1]; BbCaIt
} bCfw,V{sce
nEndPos[nEndPos.length-1] = nFileLength; T8t_+|( G
} 07 E9[U[
} d_] sV4[
pP|LSrY!
bmP2nD6
//启动子线程 0wE)1w<C~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O'.sK pXe
for(int i=0;i<nStartPos.length;i++) xf|vz|J?y
{ *]K/8MbiF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o=)["V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Dkyw3*LCn%
nStartPos,nEndPos,i); ;N?raz2mEi
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @3v[L<S{
fileSplitterFetch.start(); -Cc2|~n
} g3*J3I-O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Va-.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1e)5D& njS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -qs R,H
nEndPos = " + nFileLength); L"[>tY
// fileSplitterFetch[nPos.length-1].start(); 3uy^o
0 zn }l6OS
qe_qag9
//等待子线程结束 {oVoN>gp
//int count = 0; Qj3l>O
//是否结束while循环 =N^j:t
boolean breakWhile = false; U UYx-x
f?BApm
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while(!bStop) ., =\/ C<
{ d>gN3}tT
write_nPos(); .|c=]_{
Utility.sleep(500); *-,jIaL;
breakWhile = true; H$)__V5I,q
{^A,){uX]
S4C4_*~Vd
for(int i=0;i<nStartPos.length;i++) njGZ#{"eC
{ q]rqFP0C
if(!fileSplitterFetch.bDownOver) e13' dCG
{ 78h!D[6
breakWhile = false; AYHefAF<w
break; Wagb|B\
} S]g`Ds<
} 9Ac4'L
if(breakWhile) bFB.hkTP
break; ,7os3~Mk9
e\95X{_'
X$(YCb
//count++; +2JC**)I
//if(count>4) ]&_z@Z.i
// siteStop(); e3=-7FU
} P;V5f8r?
r}M2t$nv
VpyqVbx1
System.err.println("文件下载结束！"); EXizRL-9o
} %d^ =$Q
catch(Exception e){e.printStackTrace ();} LA4,o@V`
} jn._4TQ*}
d Z P;f^^
`%$l b:e
//获得文件长度 u!TMt8+c
public long getFileSize() ;.I,R NM
{ lnWscb3t
int nFileLength = -1; =y]FcxF
try{ a"!r]=r
URL url = new URL(siteInfoBean.getSSiteURL()); s0/y> ok
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q7(I'
httpConnection.setRequestProperty("User-Agent","NetFox"); XGSgx
WKB K)=
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int responseCode=httpConnection.getResponseCode(); H]PEE!C;xC
if(responseCode>=400) 4O'%$6KR(
{ fp2uk3Bm[
processErrorCode(responseCode); WVdF/H
return -2; //-2 represent access is error [;$9s=:[
} ;t\C!A6
KvNw'3Ua
i'MpS
String sHeader; H|s,;1#
5NN`tv
+P|Z1a -jB
for(int i=1;;i++) 7CSd}@71\
{ u iR[V~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zw}Wm4OH
//Utility.log(in.readLine()); G~{#%i
sHeader=httpConnection.getHeaderFieldKey(i); SGUZ'}
if(sHeader!=null) Z ItS(oJ.
{ -m_H]<lWZ
if(sHeader.equals("Content-Length")) i _YJq;(
{ 2+}hsGnp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IP+.L]S
break; *DuP~8
} (3QG
} >"<<hjKJ
else dH~i
break; [w?v !8l
} Y~P* !g
} q4]Qvf>
catch(IOException e){e.printStackTrace ();} `Oe"s_O#
catch(Exception e){e.printStackTrace ();} *ulkqpO
H'x)[2
}HxC~J"
Utility.log(nFileLength); W3]?>sLE*
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return nFileLength; E=RX^ 3+}
} gi JjE
j7 \y1$w
f!13Ob<8r
//保存下载信息（文件指针位置） P*3PDa@
private void write_nPos() * %w8bB
{ 2'7)D}p
try{ UY/qI%#L#,
output = new DataOutputStream(new FileOutputStream(tmpFile)); FV5~sy
output.writeInt(nStartPos.length); 2i~zAD'
for(int i=0;i<nStartPos.length;i++) N&]_U%#Q
{ +J <<me4
// output.writeLong(nPos); 4C`p`AQqpQ
output.writeLong(fileSplitterFetch.nStartPos); DNGj81'c
output.writeLong(fileSplitterFetch.nEndPos); x?n13C
} +W^$my)<
output.close(); 7qEc9S@
} df7xpV
catch(IOException e){e.printStackTrace ();} oWV^o8& GH
catch(Exception e){e.printStackTrace ();} ;[!W*8.c
} ?.6fVSa
o>@9[F,h+
Ht&%`\9s
//读取保存的下载信息（文件指针位置） _7N^<'B
private void read_nPos() gbjql+Mx+
{ N5Ih+8zT
try{ (i>bGmiN
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lj"72
int nCount = input.readInt(); ' qN"!\
nStartPos = new long[nCount]; v<V9Z <ub
nEndPos = new long[nCount]; C$7dmGjZ
for(int i=0;i<nStartPos.length;i++) LseS8F/q
{ ]C5/-J,F
nStartPos = input.readLong(); 2M*84oh8P
nEndPos = input.readLong(); 7"s8G7
} [Q:mLc
input.close(); vl:V?-sY
} k_](u91
catch(IOException e){e.printStackTrace ();} C~8;2/F7
catch(Exception e){e.printStackTrace ();} f<Xi/(
} Ue!~|:
#Y<(7
TRku(w1f
private void processErrorCode(int nErrorCode) N\W4LO6
{ 4<q'QU#l<
System.err.println("Error Code : " + nErrorCode); gYW
} TUM7(-,9
ZGC*BP/
3#~w#Q0%
//停止文件下载 +JPHQx'W
public void siteStop() f~v@;/HL
{ nW!pOTJq21
bStop = true; &ngG_y8}&
for(int i=0;i<nStartPos.length;i++) (VB-5&b
fileSplitterFetch.splitterStop(); NG\^>.8
">!<OB
o 76QQ+hP
} OE5JA8/H
} [hXnw'Im/
//负责部分文件的抓取 F8>J(7On
**FileSplitterFetch.java K&UTs$_cI
*/ $pfN0/`(
package NetFox; Z{rD4S@^
,Ep41v;T%`
LRKl3"M
import java.io.*; v)-:0f
import java.net.*; y4`uU1=
)~=g}&
N^xk.O_TO
public class FileSplitterFetch extends Thread { AlhPT (
} DQ KfS
P= nu&$;
String sURL; //File URL ^^{7`X u
long nStartPos; //File Snippet Start Position *$v`5rP
long nEndPos; //File Snippet End Position CK#SD|~:
int nThreadID; //Thread's ID lt{yo\
boolean bDownOver = false; //Downing is over e2vLUlL8
boolean bStop = false; //Stop identical @V71%D8{
FileAccessI fileAccessI = null; //File Access interface #/2W RN1L
XS`=8FQ
6}^6+@LG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uH=^ILN.
{ ;SVAar4r
this.sURL = sURL; !1fAW!8
this.nStartPos = nStart; }8)iFP&"
this.nEndPos = nEnd; sq1v._^s
nThreadID = id; >%Nqgn$V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 khS >
} ^K`Vqo
KdU&q+C^
@zAav>
public void run() 6qq{JbK
{ :?J0e4.]
while(nStartPos < nEndPos && !bStop) 8 rA'd
{ {aVL3QU
oC >l|?h,
pjrzoMF
try{ 4j VFzO%.
URL url = new URL(sURL); PYJ8\XZ1_N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5`Oaf\S
httpConnection.setRequestProperty("User-Agent","NetFox"); v]e6CZwo
String sProperty = "bytes="+nStartPos+"-"; >TB Rp,;r
httpConnection.setRequestProperty("RANGE",sProperty); m8C scCZ}
Utility.log(sProperty); Mi2lBEu,
uZkh.0yB
o}VW%G"
InputStream input = httpConnection.getInputStream(); IPEJ7n49
//logResponseHead(httpConnection); O\ph!?L
Hsvu&>[`S
XR.Sm<A[
byte[] b = new byte[1024]; 026|u|R
int nRead; J'4V_Kjg-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Az4a|.
{ NkL>ru!b9
nStartPos += fileAccessI.write(b,0,nRead); D?6ah=:&R
//if(nThreadID == 1) J4>k9~q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]] Jg%}o
} _{f7e^;
GK\`8xWE
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Utility.log("Thread " + nThreadID + " is over!"); +VdC g_
bDownOver = true; @-H D9h
//nPos = fileAccessI.write (b,0,nRead); _tO:,%dL
} `8<h aU
catch(Exception e){e.printStackTrace ();} Kta7xtu
} 4M{]YZMw8
} fkWTO"f-
@l^BW*BCo
6O# xV:Uc<
//打印回应的头信息 qGH\3g-
public void logResponseHead(HttpURLConnection con) HI*j6H?\
{ $ ";NS6 1
for(int i=1;;i++) G@I/Dy
{ :bBMy\(u
String header=con.getHeaderFieldKey(i); KQv97#n1
if(header!=null) Ub9p&=]h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `zBQ:_3J_
Utility.log(header+" : "+con.getHeaderField(header)); BkcA_a:W
else |*[#Iii'
break; ds|L'7
} P K9BowlW
} Ki{]5Rz
'H.,S_v1x
PS3%V_2
public void splitterStop() ?84B0K2Ns
{ )AoF-&,w
bStop = true; t$yt8#Tk
} ?PSVVUq,Z
jZLD^@AP
1Z| {3W
} gW(7jFl
nD/; Gq
(TQhO$,
/* C#Y_La
**FileAccess.java u~VvGLFf5,
*//文件访问(定位，写) c"x-_Uk
package NetFox; 8 DE%ot
import java.io.*; 3El5g0'G
B9(e"cMm
_8eN^oc%
public class FileAccessI implements Serializable{ ZclZD{%8J
BiI}JEp4o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0CFON2I
RandomAccessFile oSavedFile; syR +;
long nPos; #:st>V_h
Y,;$RV@g
#k*P/I~
public FileAccessI() throws IOException xY,W[?3CY
{ x;L.j7lzA;
this("",0); 'hn=X7
} /ig'p53jL
1j":j%9M
+kN/-UsB
public FileAccessI(String sName,long nPos) throws IOException QYj8c]8f
{ w +~,Mv\
oSavedFile = new RandomAccessFile(sName,"rw"); x8q3 Njr
this.nPos = nPos; |r%lJmBB
oSavedFile.seek(nPos); xHo iu$i6
} $b=4_UroS
s`E^1jC
u^NZsuak
public synchronized int write(byte[] b,int nStart,int nLen) dOfEEqPI
{ &Y/Myh[P
int n = -1; Fo86WP}
try{ vx&r
oSavedFile.write(b,nStart,nLen); @& vtY._
n = nLen; 2^.qKY@g@
} ZN]LJ4|xu
catch(IOException e) Am&PH(}L
{ e6JT|>9A7
e.printStackTrace (); n0*a.
} f+o%N
Pk6l*+"r<
B[Gl}(E
return n; lmjoSINy
} @4%a
3+` <2TP
"spAYk\
} _Boe"
Sy?O(BMo
L dyTB@
/* B}y`E <
**SiteInfoBean.java (ev(~Wc
*/ >lg-j-pV
package NetFox; O?I~XM'S
">V.nao
TtZ '~cGR
public class SiteInfoBean { bw\a\/Dw
(&y~\t]H
)n&@`>vm
private String sSiteURL; //Site's URL Spt]<~
private String sFilePath; //Saved File's Path =5QP'Qt{O
private String sFileName; //Saved File's Name 6JYVC>i
private int nSplitter; //Count of Splited Downloading File w?LDaSz\t
l0%qj(4`6&
N-g=_86C"
public SiteInfoBean() [LHx9(,NM
{//nSplitter的缺省值为5 A^9RGz4=
//default value of nSplitter is 5 %1Pn;bUU!
this("","","",5); hb_J.Q
} ?k7z5ow
?9)-?tZ^Q
wh~g{(Xvq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .7"]/9oB
{ |z`kFil%
sSiteURL= sURL; Eoo[)V#x{
sFilePath = sPath; v|r=}`k=
sFileName = sName; viP.G/(\]
this.nSplitter = nSpiltter; t"]+}]O
hCcAAF*I;5
#ARQB2V
} |*w}bT(PfR
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uR:@7n
public String getSSiteURL() @},25"x)
{ p[zKc2TPk
return sSiteURL; ?k*%r;e>
} 3~mi
9 Z5!3
!Xzne_V<
public void setSSiteURL(String value) JQtBt2
{ tf5h/:
sSiteURL = value; s$,gM,|cK
} #J,?oe=<4
N5SePA\ ,?
*C*'J7
public String getSFilePath() yX'f"*
{ uV@#;c4
return sFilePath; RzOs,
} /7)l22<
L/U^1=Wi*O
\:To>A32
public void setSFilePath(String value) dV( "g],
{ $z>L $,c>
sFilePath = value; 2;z~xR
} E W{vF|
zP8a=Iv
nSM8o<)H
public String getSFileName() %rmn+L),;
{ \.`;p
return sFileName; Pr%Y!|
} K9*vWoP'
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c8^M::NI
public void setSFileName(String value) $@[`v0y*
{ w4m)lQM
sFileName = value; <h*r
} xDU{I0M
4NY}=e5
sr=~Uq{g
public int getNSplitter() gNsas:iGM
{ /mM#nS
return nSplitter; o<Esh;;*nm
} -Dx_:k|k
\x,q(npHi
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public void setNSplitter(int nCount) r?w^#V
{ N'8u}WO
nSplitter = nCount; Y M<8>d
} vH^6O:V
} 'K L"i
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(&W&1KT
/* UcHe"mn
**Utility.java Cm~Pn"K_]
*/ g p2S
package NetFox; 2+2Gl7" s
bI_6';hq!
v `a:Lj
public class Utility { sUCI+)cM3
cILI%W1
Tke3X\|
public Utility() ~6)A/]6
{ Mx3MNX/
7O=N78M
bp>-{Nv
} &^v5 x"
pn:) Rq0
//线程睡眠 X{ZcJ8K
public static void sleep(int nSecond) Z8X=Md8=
{ ;V=Y#|o
try{ bc?\lD$$
Thread.sleep(nSecond); {Tps3{|wt
} pdz_qj!Z
catch(Exception e) d3m!34ml
{ '@ $L}C#OI
e.printStackTrace (); o*[n[\cR
} kK0.j)(
} Q|DVB
e={X{5z0
//日志 xzZ2?zWi
public static void log(String sMsg) Tuk:: .jD
{ H8'q Y
System.err.println(sMsg); B#+0jdF;
} o#D;H[' A
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va`/Dp)M
public static void log(int sMsg) M/O Y "eL
{ m#i5}uHHg
System.err.println(sMsg); 8NE+G.:G
} >{v,HOxl
} wX!q dII)
Z~?1xJ&
]#7{x
/* QGR}`n2D
**TestMethod.java 0Z m^6T
*/ gXNlnh%?S
package NetFox; \W,,@-
bPlqS+ai_
@PaOQ@
public class TestMethod { T4M"s;::1
,w9:)B7
j$<sq
public TestMethod() Z7="on4
{ ///xx/weblogic60b2_win.exe \Nvu[P
try{ cbton<r~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?ufX3yia
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); eTeZ^G
SiteFileFetch fileFetch = new SiteFileFetch(bean); ef Moi'v
fileFetch.start(); l\HLlwYO
} Q{:5gh
catch(Exception e){e.printStackTrace ();} c*k%r2'
]T?Py)
8JFns-5
} <Lt%[dn
yx@%x?B
E.'v,GYe
public static void main(String[] args) At0ahy+
{ _s1pif
new TestMethod(); Jp d|<\Ml
} e#5LBSP
} 'o!{YLJ fM
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