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)); Lz'VQO1U=
} MxIa,M<
for(int i=0;i<nEndPos.length-1;i++) QS&B"7;g
{ rTIu'
nEndPos = nStartPos[i+1]; 6(f'P_*
} Yg^ &4ZF
nEndPos[nEndPos.length-1] = nFileLength; LZRg%3.E
} xf]K
} ]$@D=g,r
;mG*Rad
`.W2t5Y
//启动子线程 `x`[hJ?i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +O.-o/
for(int i=0;i<nStartPos.length;i++) 2M-[x"\1/
{ >5t%_/yeB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 64zOEjra
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5*pzL0,Y
nStartPos,nEndPos,i); tg/UtE`V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TJO$r6&
fileSplitterFetch.start(); %M@K(Qu
} U%nkPIFm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l}))vf=i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 27e!KG[&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YB5"i9T2
nEndPos = " + nFileLength); FvxM
// fileSplitterFetch[nPos.length-1].start(); _s=H|#l
lD/9:@q\V
'BjTo*TB]Z
//等待子线程结束 ,twx4r^
//int count = 0; esqmj#G
//是否结束while循环 @Nek;xJ
boolean breakWhile = false; /*mF:40M;
<OMwi9
"<!U
while(!bStop) aixX/se
{ JL1ajlm~
write_nPos(); WEimJrAn
Utility.sleep(500); ::|~tLFu
breakWhile = true; 8b2 =n
}X&rJV
hy5[ L`B
for(int i=0;i<nStartPos.length;i++) "jFf}"
{ )D,KG_7l
if(!fileSplitterFetch.bDownOver) t~) P1Lof\
{ A9$x8x*Lt
breakWhile = false; o$rjGa l
break; k {*QU(
} ysW})#7X
} &]nx^C8V;
if(breakWhile) hJb2y`,q
break; z%82Vt!a5
7zb^Z]
b dgkA
//count++; }e?H(nZS7h
//if(count>4) /<J(\;Jr6
// siteStop(); .-KI,IU
} $5R2QNg n
cMw<3u\
6>a6;[
System.err.println("文件下载结束！"); m9 h '!X<
} > N~8#C
catch(Exception e){e.printStackTrace ();} 35<A:jKS
} r )F;8(
h.jJAVPi
4l$OO;B
//获得文件长度 k?+ 7%A]
public long getFileSize() l|P"^;*zq
{ B*(]T|ff<
int nFileLength = -1; p)y5[HX
try{ j/O~8o&
URL url = new URL(siteInfoBean.getSSiteURL()); [FO4x`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c|&3e84U
httpConnection.setRequestProperty("User-Agent","NetFox"); 7n8nJTU{4j
a+w2cN'
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int responseCode=httpConnection.getResponseCode(); Re$h6sh
if(responseCode>=400) G;Li!H
{ (Rw<1q`,
processErrorCode(responseCode); KGz Nj%
return -2; //-2 represent access is error 1/.BP
} A~?M`L>B
,i2-
ig,.>'+l
String sHeader; o*cu-j3
d*@T30
e97G]XLR
for(int i=1;;i++) <xI<^r'C9e
{ X?5{2ulrI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8 #_pkVQw:
//Utility.log(in.readLine()); O=B=0
sHeader=httpConnection.getHeaderFieldKey(i); De?VZ2o9"
if(sHeader!=null) fF@w:;u
{ ;qshd'?*
if(sHeader.equals("Content-Length")) Bn}woyJdx
{ \T7Mt|f:5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a>wCBkD
break; Y6` xb`
} rq+_[!
} xe@1H\7:
else y>I2}P
break; l5[5Y6c>
} 2Ez<Iw
} w'S,{GW
catch(IOException e){e.printStackTrace ();} >>U>'}@Q
catch(Exception e){e.printStackTrace ();} LOh2eZ"n
d>QFmsh-
HBlk~eZ
Utility.log(nFileLength); 50,'z?-_
!nvwRQ
#@R0$x
return nFileLength; B `(jTL
} Z(mUU]
\TV
XkaREE
//保存下载信息（文件指针位置） 1[FN: hm
private void write_nPos() bZqTT~'T
{ J=g)rd[`
try{ =RoG?gd{R
output = new DataOutputStream(new FileOutputStream(tmpFile)); eV9U+]C`
output.writeInt(nStartPos.length); pv_o4qEN
for(int i=0;i<nStartPos.length;i++) -`O{iHfM|P
{ f1 ;
// output.writeLong(nPos); VD;*UkapZx
output.writeLong(fileSplitterFetch.nStartPos); m'o dVZ7
output.writeLong(fileSplitterFetch.nEndPos); .wfydu)3
} $O"ss>8Se
output.close(); YF%gs{
} T &ZQie/
catch(IOException e){e.printStackTrace ();} dWAt#xII
catch(Exception e){e.printStackTrace ();} kf, &t
} Iy<>-e"|
>jm(2P(R
afm\Iv[*
//读取保存的下载信息（文件指针位置） LEb$Fd
private void read_nPos() s,z~qL6&
{ 19!?oeOU
try{ PX:#+bq1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;Qi:j^+P)
int nCount = input.readInt(); =pH2V^<<#
nStartPos = new long[nCount]; DIC*{aBf
nEndPos = new long[nCount]; a<cwrDZ
for(int i=0;i<nStartPos.length;i++) amBg<P`'_
{ JcAsrtrG]
nStartPos = input.readLong(); \J'}CX*aQ
nEndPos = input.readLong(); kDmm
} R9XU7_3B
input.close(); t{md&k4
} YQMWhC,8hy
catch(IOException e){e.printStackTrace ();} 0vY_
catch(Exception e){e.printStackTrace ();} (3Db}Hnn
} I2[U#4n
'&IGdB I
I"Oq< _
private void processErrorCode(int nErrorCode) MIMC(<
{ X/5m}-6d]
System.err.println("Error Code : " + nErrorCode); `#""JTA"
} [doEArwn
s68(jYC7[
X\^V{v^-
//停止文件下载 wJp<ZL
public void siteStop() hnj\|6L
{ u]p21)m$x
bStop = true; waMF~#PJlt
for(int i=0;i<nStartPos.length;i++) WAu>p3
fileSplitterFetch.splitterStop(); NxP(&M(
&:&'70Ya
lC<;Q*Y
} 'zyw-1
} }(EH5jZ'
//负责部分文件的抓取 !fOPYgAGKn
**FileSplitterFetch.java epy2}TI
*/ zsL@0]e&
package NetFox; 9+ 'i(q z
rXx#<7`
-TUJ"ep]QJ
import java.io.*; 6VW*8~~Xy
import java.net.*; uibmQ|AQ
XKp&GE@Y
8^7Oc,:~
public class FileSplitterFetch extends Thread { I)rnF
qng ~,m
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String sURL; //File URL ImXYI7PL
long nStartPos; //File Snippet Start Position \&"C
long nEndPos; //File Snippet End Position \xYVnjG,
int nThreadID; //Thread's ID 4Aj~mA
boolean bDownOver = false; //Downing is over "@Vyc6L
boolean bStop = false; //Stop identical YxF@1_g
FileAccessI fileAccessI = null; //File Access interface sd%j&Su#4
(7 I|lf e
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0 R6:3fV6R
{ 8Qvs\TY
this.sURL = sURL; `v*HH}aDO
this.nStartPos = nStart; 5`h$^l/
this.nEndPos = nEnd; lM-9J?j
nThreadID = id; J%"BCbxW~B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0|&@)`
} @MSmg3&
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public void run() c^}y9% 4c
{ 80lei
while(nStartPos < nEndPos && !bStop) '*J+mZtN
{ ]!/
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&@iOB #H
try{ r:*G{m-
URL url = new URL(sURL); ON2o^-%=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j=r1JV @
httpConnection.setRequestProperty("User-Agent","NetFox"); IeYYG^V<A
String sProperty = "bytes="+nStartPos+"-"; g~hMOI?KK^
httpConnection.setRequestProperty("RANGE",sProperty); omE- c
Utility.log(sProperty); I&-r^6Yx
IuwE&#
!"^Zr]Qt+\
InputStream input = httpConnection.getInputStream(); vJWBr:`L
//logResponseHead(httpConnection); JR!-1tnc
jTa\I&s,A
4H{t6t@-:
byte[] b = new byte[1024]; 7^dr[.Q[*
int nRead; tZ_'>7)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ale'-V)5
{ z; GQnAG@
nStartPos += fileAccessI.write(b,0,nRead); f-%M~:
//if(nThreadID == 1) ,`geOJn'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n`, <g
} e=i X]%^
Oeh A3$|#
PaCCUF
Utility.log("Thread " + nThreadID + " is over!"); hRf l\Q[
bDownOver = true; wJC[[_"3 I
//nPos = fileAccessI.write (b,0,nRead); $d<NN2
} lV\iYX2#
catch(Exception e){e.printStackTrace ();} EGXvz)y
} J"aw 1
} u)@:V)z
.S//T/3O]Q
63l3WvoK
//打印回应的头信息 |]7c&`
public void logResponseHead(HttpURLConnection con) BUXE s0]Lv
{ SBxpJsW>
for(int i=1;;i++) ?+zFa2J
{ +|/0sPW(
String header=con.getHeaderFieldKey(i); 3x~7N
if(header!=null) D ,kxB~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ark]>4x>
Utility.log(header+" : "+con.getHeaderField(header)); ~1O|4mssS
else lHM+<Z
break; DzVCEhf
} (L(7)WbH
} Yq ]sPE92
Bsa;,
x?S86,RW
public void splitterStop() [Hh*lKg
{ !)bZ.1o
bStop = true; #)'Iqaq7
} gmVN(K}SR5
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{o~TbnC
} ,`f]mv l
|dR}S!fmG
|]G%b[
/* MT!Y!*-5
**FileAccess.java uWJJ\
*//文件访问(定位，写) 3t-STk?
package NetFox; kL DpZ{
import java.io.*; OlT8pG5Oa
8&JB_%Gb
}u;K<<h:
public class FileAccessI implements Serializable{ >haihT
%`i*SF(gV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7qqzL_d>
RandomAccessFile oSavedFile; /?;'y,(Q
long nPos; ,7d/KJ^7
[q|W*[B:@
~dS15E4-Pp
public FileAccessI() throws IOException A:m+v{*`4
{ lTC0kh
this("",0); xX-r<:'tmi
} N**)8(
/Bt!xSI
u\ _yjv#
public FileAccessI(String sName,long nPos) throws IOException CHGa_
{ k9%o{Uzy
oSavedFile = new RandomAccessFile(sName,"rw"); =\lw.59
this.nPos = nPos; e,|gr"$/
oSavedFile.seek(nPos); d.?}>jl
} 4x6n,:;
>B6*`3v
x=cucZ
public synchronized int write(byte[] b,int nStart,int nLen) $wAR cS
{ [mzed{p]]
int n = -1; h/n(
try{ jJIP $
oSavedFile.write(b,nStart,nLen); wp@_4Iq1$
n = nLen; 8?iI;(
} Cn/WNCzst&
catch(IOException e) OMK,L:poC
{ hEHd$tH06
e.printStackTrace (); Ry>y
} Ah1 9#0
6FzB-],
<\O+
return n; m%6VwV7U
} c:m=9>3
E!ndXz 59
{.2\}7.c
} #][i!9$
+%YBa'Lk
/K|(O^nw
/* TR3U<:
**SiteInfoBean.java G:1d6[Q5{
*/ ": vGs_$
package NetFox; y@!M<#SEzG
2{?]W/&fS
;j%I1k%A
public class SiteInfoBean { b$klm6nMvm
>OaD7
d@ K-ZMq
private String sSiteURL; //Site's URL O2>c|=#
private String sFilePath; //Saved File's Path 5TJd9:\Af
private String sFileName; //Saved File's Name bY#BK_8 :
private int nSplitter; //Count of Splited Downloading File Dy.i^`7\
N" L&Z4Z
l$&~(YE f
public SiteInfoBean() Os<E7l zqO
{//nSplitter的缺省值为5 F6}RPk\=i
//default value of nSplitter is 5 t~(jA9n
this("","","",5); qm$(_]R~`
} $A?9U}V#^
,jRAVt+{N
nsI+04[F
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Mw0>p5+ cy
{ o*)Sg6Yk
sSiteURL= sURL; ynmjIQ
sFilePath = sPath; - ]wT
sFileName = sName; p?f\/
this.nSplitter = nSpiltter; [uU!\xe
^:-GPr
6C&&="uww
} <kFLwF?PM'
[eD0L71[
[XY%<P3D
public String getSSiteURL() J- S.m(
{ ;(?tlFc
return sSiteURL; t}eyfflZ
} %]Z4b;W[Y
'{AB{)1
~uc7R/3ss
public void setSSiteURL(String value) qA GjR!=^
{ ]P3m=/w
sSiteURL = value; 12lX-~[["
} MoFM'a9
SyVGm@
ULAr!
public String getSFilePath() >>J3"XHX
{ 5(H%Ia
return sFilePath; upuN$4m&{
} zzZEX
C=+9XfP0
]zlA<w8
public void setSFilePath(String value) hiS|&5#
{ ^;_~mq.
sFilePath = value; ~snj92K
} L"&T3i
Z8v8@Y
_P.I+!w:x
public String getSFileName() ^0.8-RT
{ 7Jlkn=9e:
return sFileName; a%r!55.
} BI:Cm/ >
~Y x_ 3
,Iyc0
public void setSFileName(String value) .j:,WF<"l5
{ FPYk`D
sFileName = value; tkctwjD
} /Q3>w-h
R->x_9y-R
x{:U$[_
public int getNSplitter() _uO$=4Sd
{ &DMC\R*j
return nSplitter; S=k!8]/d|
} Y$L` G
+fk*c[FG
7z$Z=cs
public void setNSplitter(int nCount) ]u5TvI,C
{ Hi09?AX
nSplitter = nCount; QH-CZ6M
} fi HE`]0
} 2?~nA2+vm
$YX{gk>
6X@z(EEL
/* 'u<e<hU
**Utility.java G^Gs/- f
*/ U"7o;q
package NetFox; zgGysjV
w80X~
K(?V]Mxl6
public class Utility { dq '2y
9}6_B|
mEJ7e#
public Utility() hq7f"`
{ G0 EXgq8
P7-k!p"
]Uwp\2Bc
} "IU}>y>J
{P6Bfh7CZ
//线程睡眠 :Tpf8
public static void sleep(int nSecond) z[f]mU
{ *W8n8qG%T
try{ ZhY{,sy?QO
Thread.sleep(nSecond); 0i\>(o
} 5}G_2<G
catch(Exception e) STnMBz7
{ aE'nW_f
e.printStackTrace (); \s#~ %l
} kx(beaf
} 1;/SXJ s
b;VIR,2
//日志 ''9]`B,:a0
public static void log(String sMsg) G%sO{k7
{ 6vK`J"d{~D
System.err.println(sMsg); GUu8 N
} R%3yxnM*
Z@euO~e~
'b.jKkW7
public static void log(int sMsg) ]ePg6
{ N 8[rWJ#
System.err.println(sMsg); X}Q4;='C-
} g}hUCx(
} 1#x5 o2n
%O9Wm_%
K.yc[z)un
/* ""7H;I&
**TestMethod.java e&x)g;bn
*/ <ci(5M
package NetFox; 7;p/S#P:
bR7tmJ[)Z
cI[i v
public class TestMethod { gqv+|:#
IER;d\_V<
rS>.!DiYr,
public TestMethod() 1#N`elm
{ ///xx/weblogic60b2_win.exe Lz1KDXr`)+
try{ _t-6m2A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3YLK?X8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >aJmRA-C}
SiteFileFetch fileFetch = new SiteFileFetch(bean); C@*x
fileFetch.start(); er_6PV
} oL~1M=r
catch(Exception e){e.printStackTrace ();} Zw)=Y.y!
)vq}$W!:9
HBp??.r
} _kBmKE
n}Z%-w$K#
P\dfxR;8%
public static void main(String[] args) |\Gkhi>;
{ N$>Ml!J
new TestMethod(); j?C[ids<
} RK@K>)"f
} o%Q9]=%!
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