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)); xA-O?s"CY
} RSLMO8
for(int i=0;i<nEndPos.length-1;i++) Jp<Y2-
{ TixXA:Mf
nEndPos = nStartPos[i+1]; BK>uJv-qU
} .r/6BDE"
nEndPos[nEndPos.length-1] = nFileLength; {BBL`tg60
} Azun"F_f
} C~.7m-YW
W[]N.d7G
5sD\4g)HK
//启动子线程 _N5$>2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |RBgJkS;8
for(int i=0;i<nStartPos.length;i++) .6yC' 3~;o
{ #TLqo(/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C<GS._V&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lZ5 lmsCU
nStartPos,nEndPos,i); d`U{-?N>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }];8v+M
fileSplitterFetch.start(); +j._NRXRH
} /h=:heS4$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V/Q~NXN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8m0GxgS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1k2+eI
nEndPos = " + nFileLength); 3_JxpQg
// fileSplitterFetch[nPos.length-1].start(); oe$Y=`
5+<<:5_6l
lS.*/u*5
//等待子线程结束 ^[{\ZX
//int count = 0; _VFxzM9f
//是否结束while循环 rULrGoM
boolean breakWhile = false; y'ULhDgq^B
)N!-g47o%#
z>$AZ>t%J$
while(!bStop) iXpLcHi
{ >D'Kt?L<]m
write_nPos(); R(Y4nw+Y-
Utility.sleep(500); ]i\C4*
breakWhile = true; ^W-03
J0@ ^h
_<x4/".}B3
for(int i=0;i<nStartPos.length;i++) V_*TY6
{ k[3J5 4`g1
if(!fileSplitterFetch.bDownOver) /8 /2#`3R
{ h?H:r <
breakWhile = false; :G?6Hl)~)
break; L$*sv.
} -DgJkyt+<
} qH(3Z^#.|
if(breakWhile) G|5M~zP
break; *G|w#-\.c
C^vB&3ghi
G?\\k[#,&
//count++; Ys|n9pW
//if(count>4) '5j$wr zt
// siteStop(); /$v0Rq9
} 'Q\I@s }
<C0~7]XO
&HdzbKO=
System.err.println("文件下载结束！"); bnS"@^M
} A*)G. o:
catch(Exception e){e.printStackTrace ();} MpZ #
} f=%k9Y*)
+D ,Nd=/
hiKgV|ZD
//获得文件长度 gc|?$aE
public long getFileSize() "p<B|
{ u;$g13
int nFileLength = -1; =?Y%w%2
try{ Kfho:e,
URL url = new URL(siteInfoBean.getSSiteURL()); Ys8p,.OMs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KrwG><+j
httpConnection.setRequestProperty("User-Agent","NetFox"); FM\yf]'
}[a
5.st!Lp1
int responseCode=httpConnection.getResponseCode(); q.]>uBAQ?
if(responseCode>=400) nqX)+{wAXe
{ E3bS Q
processErrorCode(responseCode); @k_xA-a
return -2; //-2 represent access is error ~V,~'W
} +k=BD s
tBSHMz
l#!p?l
String sHeader; 6ybpPls
QH:PClW![
r q2]u
for(int i=1;;i++) nt$VH
{ ,9T-\)sT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q'r(#,B<3
//Utility.log(in.readLine()); 7A!E~/nSC
sHeader=httpConnection.getHeaderFieldKey(i); JO\F-xO
if(sHeader!=null) 9b KK
{ obYXDj2
if(sHeader.equals("Content-Length")) 2)O-EAn
{ =7&2-'(@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w}*2Hz&Q!
break; j6zZ! k
} -rC_8.u :
} fB~BVYi
else +6cOL48"
break; ZH]n&%@j
} u=epnz:<
} n}NO"eF>-s
catch(IOException e){e.printStackTrace ();} FjUf|
catch(Exception e){e.printStackTrace ();} 4.?tP7UE
N7/eF9
1A>>#M=A
Utility.log(nFileLength); FdT@}
$LxfdSa
;MD6iBD
return nFileLength; GEJEhwO;H
} eBw6k09C+
QFn .<@
R$vo
//保存下载信息（文件指针位置） p#['CqP8
private void write_nPos() F(jvdq
{ .Sz<%d7XIQ
try{ xiv1y4(%
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2<18j
output.writeInt(nStartPos.length); [ArPoJt
for(int i=0;i<nStartPos.length;i++) GR@jn]50
{ E_t ^osY&
// output.writeLong(nPos); '`.bmiM
output.writeLong(fileSplitterFetch.nStartPos); BT?)-wS
output.writeLong(fileSplitterFetch.nEndPos); dEz7 @T
} ,yZvT7
output.close(); sj@B0R=Qo
} ^zdZ"\x
catch(IOException e){e.printStackTrace ();} Z_Tu* F
catch(Exception e){e.printStackTrace ();} gQXB=ywF
} #=>t6B4af
XYeuYLut
PjL"7^Q&
//读取保存的下载信息（文件指针位置） @qC](5|TQ
private void read_nPos() }E?{M~"<
{ K,pQ11J
try{ y'gIx*6B@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lIs<&-0
int nCount = input.readInt(); v.wHj@
nStartPos = new long[nCount]; DB1F_!9
nEndPos = new long[nCount]; 37j-FLbW
for(int i=0;i<nStartPos.length;i++) C_c*21X
{ 4dfR}C
nStartPos = input.readLong(); Ygwej2
nEndPos = input.readLong(); <$#;J>{WV
} (%`R{Y
input.close(); gpo+-NnG
} Ebmd[A&&
catch(IOException e){e.printStackTrace ();} (QARle(i
catch(Exception e){e.printStackTrace ();} U _QCe+
} RgF5w<Vd.
~7$NVKE
F=/@D)hND
private void processErrorCode(int nErrorCode) ;>#YOxPl
{ s>i`=[qFc
System.err.println("Error Code : " + nErrorCode); Sb9O#$89
} bf9LR1
"mBX$t'gb
"YUh4uZ~P
//停止文件下载 -F&4<\=+
public void siteStop() 1 uKWvp0\
{ o;d><
bStop = true; #!a}ZhIt
for(int i=0;i<nStartPos.length;i++) fu}ZOPu
fileSplitterFetch.splitterStop(); ^ Tr )gik
p3sR>ToJ
h[%t7qo=
} 3%"r%:fQB/
} bV'^0(Zv
//负责部分文件的抓取 K6C@YY(
**FileSplitterFetch.java X`REhvT
*/ @wzzI 7}C
package NetFox; u0Nag=cU
g;|3n&
_A[k&nO!&J
import java.io.*; Klw\
import java.net.*; jB"?iC.
9ZKB,
yXuc<m
public class FileSplitterFetch extends Thread { KF'DOXBw>
dZSv=UY)
3,Dc}$t
String sURL; //File URL Stw%OP@?
long nStartPos; //File Snippet Start Position 0N" VOEvG
long nEndPos; //File Snippet End Position DH3.4EUWS
int nThreadID; //Thread's ID :P!"'&gCL
boolean bDownOver = false; //Downing is over 7U:-zfq
boolean bStop = false; //Stop identical O@[jNs)].
FileAccessI fileAccessI = null; //File Access interface F@+FXnz
{ S]"-x
tH7@oV;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9e`.H0
{ j,HUk,e^&
this.sURL = sURL; tC4:cX
this.nStartPos = nStart; |H!kU.f]
this.nEndPos = nEnd; mBp3_E.t
nThreadID = id; PNjZbOmzS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }"V$li
} zvzS$Gpe
N+l 0XjZD9
A,P_|
public void run() dZMOgZ.!yr
{ fR:BF47
while(nStartPos < nEndPos && !bStop) _ct18nh9
{ oNkASAd
V>8)1)dF
"kYzgi
try{ Y,?!"
URL url = new URL(sURL); CG`s@5y>5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); __F?iRrCM
httpConnection.setRequestProperty("User-Agent","NetFox"); eU[f6OGqC
String sProperty = "bytes="+nStartPos+"-"; f{} zqCK
httpConnection.setRequestProperty("RANGE",sProperty); @Lp;p$G`
Utility.log(sProperty); ?0ezr[`.
Aqc Cb[1r
fmDn1N-bG
InputStream input = httpConnection.getInputStream(); 2l7Sbs7
//logResponseHead(httpConnection); /b44;U`v5-
'aq9]D_k
Z~JX@s0v
byte[] b = new byte[1024]; 3)?v
int nRead; *{ =5AW}o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2jMV6S9
{ 72YL
nStartPos += fileAccessI.write(b,0,nRead); "*ot:;I
//if(nThreadID == 1) yB>5p]$P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H 3e(-
} M[;N6EJH
Qh3V[br
QG|KZ8uO
Utility.log("Thread " + nThreadID + " is over!"); vf|lF9@U
bDownOver = true; } Fw/WD
//nPos = fileAccessI.write (b,0,nRead); 0<,Q7onDD:
} +IRr&J*P
catch(Exception e){e.printStackTrace ();} pPC_ub
} 0:,8Ce
} X2Z E9b
yq?7!X
M-K.[}}-d
//打印回应的头信息 `u./2]n
public void logResponseHead(HttpURLConnection con) 86]})H
{ S%+$
for(int i=1;;i++) YTQom!O
{ &8l4A=l$
String header=con.getHeaderFieldKey(i); Mp8FYPjZ
if(header!=null) #6jdv|fu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r_5k$u(
Utility.log(header+" : "+con.getHeaderField(header)); 6I)1[tU
else X_j=u1*5
break; 3eqVY0q
} >N&C-6W
} QGWfF,q
oAMB}a;
&#AK#`&)0i
public void splitterStop() .7BB*!CP
{ [P,/J$v^~
bStop = true; %LL*V|
} ylV.ZoY6
O_f+#K)
oX2J2O
} FY^#%0~
LC!ZeW35
#ny&bJj
/* 5i 6*$#OM_
**FileAccess.java c]pO'6]
*//文件访问(定位，写) BFCF+hU^6R
package NetFox; _?5$ST@5
import java.io.*; 2'R&K
+<^TyIJ0
+ lha=
public class FileAccessI implements Serializable{ Bn[5M[
F(-1m A&-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?q68{!{bi
RandomAccessFile oSavedFile; U?MKZL7
long nPos; 208dr*6U
nvJ2V$
p|W <xFk
public FileAccessI() throws IOException F$Cf\#{3
{ !kPZuU`T
this("",0); m&'z|eN
} ^'g1? F$_
QQd%V#M?
*@M7J
public FileAccessI(String sName,long nPos) throws IOException SqiLp!Y`
{ K?y!zy
oSavedFile = new RandomAccessFile(sName,"rw"); wbC'SOM
this.nPos = nPos; %cWy0:F5VY
oSavedFile.seek(nPos); qJ;T$W=NG
} w Wx,}=
P5:X7[
`OY_v=}
public synchronized int write(byte[] b,int nStart,int nLen) :&]THUw
{ . PzlhTL7
int n = -1; 2Z ? N
try{ dMA"% R
oSavedFile.write(b,nStart,nLen); ~}SOd<n)|
n = nLen; UUxDW3K
} ..ig jc#UF
catch(IOException e) N"i'[!H%
{ @ =RH_NB
e.printStackTrace (); =5JTVF
} +sTZ) 5vQ
=4;GIiF@
u6~|].j R
return n; o'W[v0> L-
} x?ajTzMv
.K`^n\T t
'qosw:P
} G(alM=q
u-CCUMR
{y{&tzZ
/* HWr")%EhD
**SiteInfoBean.java DhQYjC[
*/ #+1*g4m~B
package NetFox; ]LvpYRU$P
[*-DtbEk
QfI)+pf
public class SiteInfoBean { 4eSV(u)4
EZm6WvlxSI
UuV<#N)
private String sSiteURL; //Site's URL 0n<t/74
private String sFilePath; //Saved File's Path P|"U
private String sFileName; //Saved File's Name mUj=NRq
private int nSplitter; //Count of Splited Downloading File G/F0)M
@K 8sNPK
@wWro?s'p
public SiteInfoBean() J!Kk7!^|
{//nSplitter的缺省值为5 Y.O/~af
//default value of nSplitter is 5 zSYh\g"
this("","","",5); 9(%ptnya
} &Rgy/1
/4\!zPPj.
7Y:~'&U|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) oGzZ.K3 A
{ y;N[#hY#CD
sSiteURL= sURL; 0Ey*ci^ue
sFilePath = sPath; $K)9(DD
sFileName = sName; 0|0<[:(hc
this.nSplitter = nSpiltter; uvo2W!
C|kZT<,]
MIcF"fB![
} 2 {lo
`+~@VZ3m
\9T;-]
public String getSSiteURL() OzFA>FK0f;
{ WJG&`PP
return sSiteURL; L< MIl[z7
} EwSE;R -
( }DCy23
:*wnO;eN
public void setSSiteURL(String value) jk0Ja@8PK
{ C0\A
sSiteURL = value; AiXxn'&i
} 5feCA ,v7
R3]Ra&h6N)
m6P!#=a:l<
public String getSFilePath() &n% 3rC5{
{ `(|jm$Q
return sFilePath; Bc{#ia
} iJg3`1@j
:Mss"L820
Q3SwW
public void setSFilePath(String value) q]%c 6{w
{ kRBPl99
sFilePath = value; Nl_Sgyx,\
} ,B>Rc#
;>o}/h
b469
public String getSFileName() sjLI^#a
{ Vi~9[&.E\!
return sFileName; em@\S
} j HT2|VGb*
\lVX~r4
I!y[7^R
public void setSFileName(String value) }.<%46_Z-
{ ]KMOLe6(
sFileName = value; hSmu"a,S
} utq*<,^
C LhD[/Fo
JFx=X=C
public int getNSplitter() )-FQ_K%
{ !BHIp7p
return nSplitter; CVsc#=w0
} ,Yg<Z1
w, u`06
Aj06"ep
public void setNSplitter(int nCount) 28L3"c
{ PjEKZHHz
nSplitter = nCount; ]XEkQ
} &Y2mLPB
} GI}h)T
zT|]!',
.'Vjs2 2
/* XDvT#(Pu
**Utility.java <$s G]l!\
*/ irNGURLm
package NetFox; |9)Q =(
,4ftQJ
^a@Vn\V1
public class Utility { X*Mw0;+T
v>TI.;{y
WP1>)
public Utility() C%<[mM
{ p1p4t40<l
;ti{ #(Ux
WY%LeC!t
} .$>?2|gRv
gP*:>[lR
//线程睡眠 2RDos#
public static void sleep(int nSecond) 372ewh3'
{ jyPY]r
try{ (S+tQ2bt
Thread.sleep(nSecond); {#CyO b4
} K /h9x9^
catch(Exception e) jp2AU,Cl
{ AF5.gk=
e.printStackTrace (); /+G&N{)k
} Au'[|Prr
} Sk@~}
Fl GKy9k
//日志 vkan+~H
public static void log(String sMsg) 5H#3PZaQ
{ ~SkdP7 )
System.err.println(sMsg); IMzhEm
} LQSno)OZ
GeN8_i[
o>{+vwK
public static void log(int sMsg) XA{tVh
{ hQrO8T?2
System.err.println(sMsg); K"1xtpy
} 5EDM?G
} :0pxacD"!
Y3jb'S4(
DUiqt09`~
/* fL4F ~@`9l
**TestMethod.java =8 d`qS"
*/ @"T_W(i;BI
package NetFox; v"Bv\5f,Ys
v`B7[B4K3
b9HE #*d,
public class TestMethod { =rS z>l
-nG3(n&wB
O&]Y.Z9,A
public TestMethod() 1tG,V%iCp
{ ///xx/weblogic60b2_win.exe ( B$;'U<
try{ XiI@Px?FL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pLL ^R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Dm6WSp1|b
SiteFileFetch fileFetch = new SiteFileFetch(bean); Bsw5A7,-
fileFetch.start(); 94"R&|
} pU)wxv[~
catch(Exception e){e.printStackTrace ();} ]>K%,}PS
7,ODh-?ez
,dKcxp~[
} 5nzkZw
\}t(g}7T
`bO+3Y'5
public static void main(String[] args) Ps0'WRJnx
{ ' -[
new TestMethod(); d;|Pp;dc
} ciI;U/V
} z (rQ6
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