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)); fsI`DjKi)
} .@K#U52
for(int i=0;i<nEndPos.length-1;i++) i./Y w
{ 065A?KyD
nEndPos = nStartPos[i+1]; cx:jUsb6
} 8IOj[&%0
nEndPos[nEndPos.length-1] = nFileLength; B;c=eMw
} *vs~SzF$
} +Ag#B*
k2uBaj]
t>oM%/H
//启动子线程 5KaSWw/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9|a)sb7/
for(int i=0;i<nStartPos.length;i++) a71}y;W
{ me$$he
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8Mb$+^zU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OR~GOv|
nStartPos,nEndPos,i); (WMLNv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g& >mP?
fileSplitterFetch.start(); 7b,AQ9
} in?T]}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gx|Dql
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SyB-iQn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ._(z~3s
nEndPos = " + nFileLength); UP*yeT,P,
// fileSplitterFetch[nPos.length-1].start(); x`3.Wu\
5j1 IH,yW
p1?J
//等待子线程结束 a;yV#Y
//int count = 0; auoA
//是否结束while循环 L]NYYP-
boolean breakWhile = false; 3H <`Z4;
gQCC>8
C=EhY+5
while(!bStop) 8fEAYRGd
{ Oo$%Yh51~
write_nPos(); MHn&; A]
Utility.sleep(500); 3]7ipwF2q
breakWhile = true; `7$Oh{67
,gx$U@0Z
^EUQ449<p
for(int i=0;i<nStartPos.length;i++) ^CX,nj_(
{ /Sh4pu"'
if(!fileSplitterFetch.bDownOver) IjgBa-o/V
{ MIJ%_=sm4:
breakWhile = false; 8ZzU^x
break; A7e_w 7?a
} Qvs(Rt3?y
} WT1q15U(=
if(breakWhile) roL]v\tr
break; ^ M8k
3XBp6`
GMt)}Hz
//count++; 25w6KBTe;:
//if(count>4) Ic_tc
// siteStop(); eKS:7:X
} 1=- X<M75
ap{{(y&R
tTE3H_
System.err.println("文件下载结束！"); wfWS-pQ
} w7Pe
catch(Exception e){e.printStackTrace ();} _i#@t7
} Mj,2\ijNM
P'gT6*an,"
v3!byN^
//获得文件长度 = c/3^e
public long getFileSize() }]Qmt5'NI
{ >DkN+S
int nFileLength = -1; bmSpbX\
try{ <w%Yq?^
URL url = new URL(siteInfoBean.getSSiteURL()); VQ/ <09e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 18J.vcP
httpConnection.setRequestProperty("User-Agent","NetFox"); JJ*0M(GG
M_|M&lR>
)moo?Q
int responseCode=httpConnection.getResponseCode(); n,1NJKX
if(responseCode>=400) \qRjXadj
{ t>m8iS>
processErrorCode(responseCode); #r-j.f}yx
return -2; //-2 represent access is error 0 [*nAo
} 38OIFT
Z={UM/6w
zd.1
String sHeader; mJ7`.
/0X0#+kn
|~Htj4K/
for(int i=1;;i++) LAOdH/*:
{ LZ3rr-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #wq;^)>
//Utility.log(in.readLine()); F<H`8*q9
sHeader=httpConnection.getHeaderFieldKey(i); %'$cH$%~J
if(sHeader!=null) Ma n^\gkCi
{ b0rt.XB
if(sHeader.equals("Content-Length")) =]2 b8
{ |F8;+nAVF#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $@lq}FQ%
break; ~Q3WBOjn
} O1l4gduN|i
} Q';\tGy
else 5EVB27k
break; D>,$c
} DtI%-I.
} P6.)P|n7=
catch(IOException e){e.printStackTrace ();} 1e+h9|hGYw
catch(Exception e){e.printStackTrace ();} S]Yu6FtWiO
9Ba|J"?Y k
,APGPE}I[
Utility.log(nFileLength); K gR1El.r
HCfS)`
#S/pYP`7
return nFileLength; >'BU*
} sPZV>Q:zY
IIYX|;1}X
(\[jf39e
//保存下载信息（文件指针位置） z+5u/t
private void write_nPos() bw<~R2[
{ GN}9$:
try{ 6x`\ J2x
output = new DataOutputStream(new FileOutputStream(tmpFile)); od|N-R
output.writeInt(nStartPos.length); _Ct@1}aa4x
for(int i=0;i<nStartPos.length;i++) [rD+8,zVm
{ kM6 EZ`mj
// output.writeLong(nPos); SF78s:_!_
output.writeLong(fileSplitterFetch.nStartPos); :BC<+T=
output.writeLong(fileSplitterFetch.nEndPos); z22|Kv;w
} OsHkAI
output.close(); zEA{%)W
} .q~,.yI&j
catch(IOException e){e.printStackTrace ();} >Gw%r1)
catch(Exception e){e.printStackTrace ();} CU} q&6h
} [hvig$L
&</@0
C {H'
//读取保存的下载信息（文件指针位置） 3P<Zzt%eT
private void read_nPos() ^*4(JR
{ 7J)a"d^e
try{ Nys'4kx7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J$eZLj
int nCount = input.readInt(); & Q|f*T
nStartPos = new long[nCount]; iZVT% A+q
nEndPos = new long[nCount]; ;]8p:ME
for(int i=0;i<nStartPos.length;i++) H/ B^N,oi
{ CC]@`R5
nStartPos = input.readLong(); Is#v6:#^
nEndPos = input.readLong(); U:T5o]P<
} cZ7F1H~
input.close(); b5iJm-
} SOi(5]
catch(IOException e){e.printStackTrace ();} ~ 33@H
catch(Exception e){e.printStackTrace ();} t9=|* =;9)
} }I'>r(K
q>Ar.5&M_
`G:qtHn"Q<
private void processErrorCode(int nErrorCode) ?_<UOb*
{ X/?h!Y}
System.err.println("Error Code : " + nErrorCode); rE' %MiIK
} 6:7:NIl:
jv?aB
k6 h^
//停止文件下载 1v8:,!C
public void siteStop() dBi3ZCAF
{ S+bWD7
bStop = true; CUTEp/+
for(int i=0;i<nStartPos.length;i++) } cH"lppX
fileSplitterFetch.splitterStop(); .k?hb]2N
t]YLt ,
nk?xNe4
} N]P*6sf-6
} cJp1 <R
//负责部分文件的抓取 Dv\:b*
**FileSplitterFetch.java ^FpiQF
*/ =[CS2VQ'
package NetFox; hH@o|!y
<:_]Yl
l{7Dv1[Ss
import java.io.*; u/c~PxC
import java.net.*; y<gYf -E+
c)P%O
e"&9G}.f
public class FileSplitterFetch extends Thread { ]|\>O5eeu
ct4)faM
/%@RO^P
String sURL; //File URL @#O|
long nStartPos; //File Snippet Start Position &,gryBN
long nEndPos; //File Snippet End Position nR|uAw
int nThreadID; //Thread's ID (>@syF%PB
boolean bDownOver = false; //Downing is over vp}>#&
boolean bStop = false; //Stop identical V,*0<7h
FileAccessI fileAccessI = null; //File Access interface ?@uK s4
?PU(<A+
,`B>}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j2v[-N4 {J
{ '/]Aaf@U8
this.sURL = sURL; d)J] Y=j
this.nStartPos = nStart; W$ d{
this.nEndPos = nEnd; k=q%FlE
nThreadID = id; `OpC-Z&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ObHz+qRG
} = ,E(!Sp
_xZb;PbFE
0kr& c;~
public void run() Ss#{K;
{ JqV<A3i
while(nStartPos < nEndPos && !bStop) J*4_|j;Z-E
{ \crb&EgID
JbD)}(G;
Vm%ux>}
try{ DD{@lM\vc
URL url = new URL(sURL); 1:l&&/Wy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dUVTQ18F
httpConnection.setRequestProperty("User-Agent","NetFox"); 4!b'%)
String sProperty = "bytes="+nStartPos+"-"; VBj;2~Xj4h
httpConnection.setRequestProperty("RANGE",sProperty); K&~#@I;
Utility.log(sProperty); o9SfWErZ
b}{9 :n/SC
>|&OcU
InputStream input = httpConnection.getInputStream(); L08;z
//logResponseHead(httpConnection); 5~rY=0t
T!eh?^E
.Y Frb+6
byte[] b = new byte[1024]; ofhZ@3
int nRead; `0gK;D8t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WOTu"Yj
{ ` vmk
nStartPos += fileAccessI.write(b,0,nRead); a9q?9X
//if(nThreadID == 1) C(Gb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T/.y(8!0I8
} BE@H~<E J
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vBQ?S2f
Utility.log("Thread " + nThreadID + " is over!"); TKutO0
bDownOver = true; {_gj>n(1
//nPos = fileAccessI.write (b,0,nRead); G5@fqh6ws
} q9Opa2
catch(Exception e){e.printStackTrace ();} Fm+)mmJP
} 'C4Ll2
} N`GwL aF
&=t(NI$
s*U&[7P
//打印回应的头信息 ?fX8WRdh
public void logResponseHead(HttpURLConnection con) rVW'KN
{ |4*2xDcl
for(int i=1;;i++) v7I*W/
{ -2u+m
String header=con.getHeaderFieldKey(i); ,rPyXS9Sa{
if(header!=null) OL+40J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >qGR^yvb
Utility.log(header+" : "+con.getHeaderField(header)); cO?"
else R$,iDv.jI
break; @V CQ4X7T
} #)eJz1~
} T#;*I#A:
(ZR"O8
SPm5tU
public void splitterStop() s~ZC!-[;
{ r*xw\
bStop = true; ?4||L8j2^
} <(lSNGv5N
?mUu(D:7D
Uwil*Jh
} o5A_j?t
?)<XuMh
xb_:9
/* a^1c _
**FileAccess.java I*ni)Px
*//文件访问(定位，写) rKO*A7vE
package NetFox; %QZ!Tb
import java.io.*; <"P '"SC
S;<?nz3
e-av@a3
public class FileAccessI implements Serializable{ s+~Slgl
L2A#OZZu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &H>dE]Hq,
RandomAccessFile oSavedFile; I,uu>-
long nPos; cCCplL
DLM9o3/*J
8-lY6M\R\
public FileAccessI() throws IOException 51'SA B09
{ q%&7J<
this("",0); _cs9R%
} \r9%;?f
QQ8W;x
#IwB
public FileAccessI(String sName,long nPos) throws IOException /Day5\Q#
{ {j@)sDMX
oSavedFile = new RandomAccessFile(sName,"rw"); ?b$zuJ]
this.nPos = nPos; BC[d={_-
oSavedFile.seek(nPos); pU'sADC
} ^( VB5p
JNl+UH:.
v%Q7\X(
public synchronized int write(byte[] b,int nStart,int nLen) *0zH5c
{ zSXC
int n = -1; ~jTnjx
try{ Qeog$g.HI
oSavedFile.write(b,nStart,nLen); *G=AhH$t
n = nLen; c'qM$KN9G
} L` "UeNT
catch(IOException e) B.WkHY%/
{ j( :A
e.printStackTrace (); zPc;[uHT
} dEL"(e#0s4
$8}'6,
MF(~!SOIG
return n; 3%a37/|~y
} :.Sc[UI0
8;NO>L/J]i
P9^h>sV
} =*U24B*U93
@>j \~<%
c[7qnSH
/* dVfDS-v!
**SiteInfoBean.java g_X7@Dt
*/ h)`vc#"65k
package NetFox; `:4cb$
ijYLf.R<
va;wQ~&
public class SiteInfoBean { qZ}XjL
N|LVLsK
.>&fwG
private String sSiteURL; //Site's URL ".ZiR7Z:$Y
private String sFilePath; //Saved File's Path uoHhp4>^
private String sFileName; //Saved File's Name vsR ^aVwVZ
private int nSplitter; //Count of Splited Downloading File LeCU"~
es]m 6A
N8vl< Mq
public SiteInfoBean() c.WT5|:qw
{//nSplitter的缺省值为5 9U*vnLB
//default value of nSplitter is 5 0xcqX!(
this("","","",5); b4ivWb|`
} X>>rvlDN
xwH`alu
RGLqn{<V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) # GGmA.
{ cf'Z#NfQ
sSiteURL= sURL; ?Gfe?
sFilePath = sPath; V:J6eks_
sFileName = sName; Us5JnP5
this.nSplitter = nSpiltter; '3->G/Pu
N~d]}J8}gx
P|U>(9;P,
} U?{j
O=/Tx2i;
E>D@#I>
public String getSSiteURL() swA"_A8>u
{ W~FA9Jd'Z
return sSiteURL; ](D [T
} s#[Ej&2[=
STI3|}G*P
) b8*>k
public void setSSiteURL(String value) )^+$5OR\c
{ 0oMMJ6"i
sSiteURL = value; TW0^wSm
} 8<xy*=%
ffVYlNQ7L
3R><AFMY?
public String getSFilePath() (" %yV_R
{ ~/%){t/uLY
return sFilePath; mUbaR
} 'z'm:|JW
enj2xye%Y
%9.KH
public void setSFilePath(String value) AF-.Nwp
{ RYNzTA
sFilePath = value; H>]x<#uz)
} =$Z'F<|d
yw0uF
?`>yl4
public String getSFileName() dp"w=~53
{ Me>'QVr
return sFileName; @C2<AmY9q*
} E \RU[
<]nI)W(
2srz) xEe
public void setSFileName(String value) 0^4*[?l9q
{ 7>LhXC
sFileName = value; J:(l&
} 67eo~~nUtg
n'H\*9t
L%"Mp(gZ
public int getNSplitter() C@-JH\{\T#
{ $j/F7.S
return nSplitter; ~0NZx8qG
} ')+EW" e
#C`!yU6(
n_<]9
public void setNSplitter(int nCount) DxBt83e
{ &}uO ]0bR
nSplitter = nCount; pK`rm"6G
} itU01
} l O^h)hrR
V4H+m,R
@b zrJ7$
/* khfE<<$=
**Utility.java or<JjTJ\o_
*/ i/L1KiCLx
package NetFox; QbWD&8T0O
&,/T<V
@'<|B. f
public class Utility { 82vx:*Ip!}
u+'=EGl
[F%\1xh
public Utility() %YXC-E3@O
{ w~9gZ&hdp
Z%Gvf~u
OW>U5 \q
} TwN8|ibVmP
-h_v(s2
//线程睡眠 k|V{jBG"@
public static void sleep(int nSecond) 580t@?
{ =h)H`
try{ Fmu R(f=
Thread.sleep(nSecond); <O WPG,
} 0c{N)
catch(Exception e) Km?i{TW
{ ICi- iX
e.printStackTrace (); DF~w20+
} NXx}KF c
} }?JO[Q +
Q pX@;j
//日志 YpL}R#
public static void log(String sMsg) xR.Ql>
{ mKg~8q 3
System.err.println(sMsg); L,<.rr$:
} u{ng\d*KE}
J L3A/^
,P|PPx%@
public static void log(int sMsg) %>.v[d1c
{ bQ)r8[o!
System.err.println(sMsg); "@n$(-.
} Dt?Fs
} 4c% :?H@2
C{))T5G
=mZw71,
/* /vMpSN|3
**TestMethod.java b?$3jOtW
*/ P'K')]D=!
package NetFox; Hq9(6w9w
iT%UfN/q=I
sxqXR6p{
public class TestMethod { ,LW0{(&z
-[F^~Gv|;
o+na`ed
public TestMethod() Z(Vrmz2.
{ ///xx/weblogic60b2_win.exe K(p1+GHC
try{ "FU|I1Xz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %vksN$^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QZ6M,\
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8_lD*bEt
fileFetch.start(); 4MIVlg9
} x83XJFPWL
catch(Exception e){e.printStackTrace ();} j@DyWm/7
@sDd:>t
jK{MU) D+
} !xvPG
>Cf`F{X'U
Jx}5`{\
public static void main(String[] args) Xy{b(b;9
{ mVkn~LD:0
new TestMethod(); L.R
} u/zC$L3B(
} JB-j@
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