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)); 7M4iBk4I
} U|>Js!$
for(int i=0;i<nEndPos.length-1;i++) a P`;Nr=
{ ka(xU#;
nEndPos = nStartPos[i+1]; 3cnsJV]
} Xd4~N:
nEndPos[nEndPos.length-1] = nFileLength; D=8=wT2<
} @8 pRIS"V
} bY`k`3v
E yNCky
,HkJ.6KF
//启动子线程 |i|O9^*%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; </fzBaTo
for(int i=0;i<nStartPos.length;i++) V3UEuA
{ ]$7|1-&Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =[P||
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f}fM%0/5
nStartPos,nEndPos,i); {5,CW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5EU3BVu&u
fileSplitterFetch.start(); B%,0zb+-L
} AojX)_"z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;HW@ZI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A;%fAI2Vr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'RPe5 vB
nEndPos = " + nFileLength); J[^-k!9M
// fileSplitterFetch[nPos.length-1].start(); vnKUD|
!$O +M#
5!wa\)wY
//等待子线程结束 m$U2|5un&
//int count = 0; y+c+/L8
//是否结束while循环 F:\CDM=lS
boolean breakWhile = false; KjhOz%Yt[o
S-im o
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while(!bStop) ,i'>+Ix<
{ j_k!9"bt
write_nPos(); 5YRa2#d
Utility.sleep(500); AH;h#dT
breakWhile = true; NpSS/rd $
[z/OY&kF
EayZ*e]
for(int i=0;i<nStartPos.length;i++) wz'D4B
{ -?j'<g0
if(!fileSplitterFetch.bDownOver) tFG&~tNc
{ >1W)J3
breakWhile = false; R+P1 +5
break; `}18A.K
} ;0 ,-ywK
} emTqbO
if(breakWhile) /CH*5w)1
break; 6z~6o0s~
BeBa4s
*S7<QyVh
//count++; X'O3)Yg
//if(count>4) Wq]^1g_
// siteStop(); M4`qi3I
} Fvg>>HVu
,XR1N$LN8_
3d[fP#NY7
System.err.println("文件下载结束！"); gd2cwnP
} li(g?|AD
catch(Exception e){e.printStackTrace ();} iOw'NxmY
} w?Y;pc}1B
@2V#bK
^`ny]3JA
//获得文件长度 K;Fy&p^d
public long getFileSize() $)6y:t"
{ I t",WFE.
int nFileLength = -1; af.yC[
try{ 67^?v)|
URL url = new URL(siteInfoBean.getSSiteURL()); N_wB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NU O9,
httpConnection.setRequestProperty("User-Agent","NetFox"); /alJN`g
T-0fVTeN
~~z}yCl
int responseCode=httpConnection.getResponseCode(); Re-4y5f
if(responseCode>=400) "H#2
{ 'V/+v#V+>
processErrorCode(responseCode); eX>x +]l6
return -2; //-2 represent access is error U8 '}(
} TF2'-"2Y
h<JV6h:8
C`Zz\DNG@
String sHeader; ><^ ,
@w?hXK=
ogtl UCUD
for(int i=1;;i++) c3lU
{ t 7dcaNBZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,Tjc\;~%
//Utility.log(in.readLine()); _ ZMoPEW
sHeader=httpConnection.getHeaderFieldKey(i); Q3T@=z2j%
if(sHeader!=null) e-Mei7{%
{ ^-Bx zOp
if(sHeader.equals("Content-Length")) C8ek{o)%W
{ DgW*Br8<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y'H|Tk^`
break; r1ao=N
} 2M@,g8O+B=
} GUSEbIz):
else )H8Rfn?
break; Dn~c
} yH/m@#
} _TEjB:9eY
catch(IOException e){e.printStackTrace ();} R.^ Y'TLyc
catch(Exception e){e.printStackTrace ();} dg-nv]7
b@`h]]~:
Bq@_/*'*Y
Utility.log(nFileLength); bi~1d"j
}hRw{#*8
ozB2L\D7
return nFileLength; [_PZdIN
} O%}?DiSl
ZMEU4?F
lub_2Cb|j
//保存下载信息（文件指针位置） Q #IlUo
private void write_nPos() x4v@o?zW
{ VUmf;~
try{ e*)*__$O
output = new DataOutputStream(new FileOutputStream(tmpFile)); -aPRLHR
output.writeInt(nStartPos.length); |kGj}v3
for(int i=0;i<nStartPos.length;i++) z[|2od
{ iC2``[m"
// output.writeLong(nPos); -?z#
output.writeLong(fileSplitterFetch.nStartPos); )xm[mvt
output.writeLong(fileSplitterFetch.nEndPos); {#y~ Qk;T
} x18(}4
output.close(); XtCG.3(LY
} _xY dnTEl
catch(IOException e){e.printStackTrace ();} Vq$8!#~w
catch(Exception e){e.printStackTrace ();} mSeCXCrZlI
} l]R=I2t
+adwEYRrr
FNlS)Bs
//读取保存的下载信息（文件指针位置） '-X[T}
private void read_nPos() .7BJq?K.
{ q<[m(]:
try{ _59f.FsVR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #K&XY6cTj
int nCount = input.readInt(); i/|}#yw8A
nStartPos = new long[nCount]; !{q_Q !
nEndPos = new long[nCount]; z_f^L %J0
for(int i=0;i<nStartPos.length;i++) g^I?u$&E
{ hU'h78bt(
nStartPos = input.readLong(); \?tE,\Ln
nEndPos = input.readLong(); uo9FLm
} u4x>gRz)
input.close(); Q%r KKOX8
} Y]VLouzl
catch(IOException e){e.printStackTrace ();} F ~SA3M:
catch(Exception e){e.printStackTrace ();} L%;fYi;n
} QZ& 4W
WA((>Daf]
+R"Y~ m{F
private void processErrorCode(int nErrorCode) B_mT[)ut
{ *[Im].
System.err.println("Error Code : " + nErrorCode); xciwKIpS
} L8,/
0@yw#.j
G,!{Q''w
//停止文件下载 G,e!!J
public void siteStop() (1e,9!?
{ ULH<FDot
bStop = true; @)XR
for(int i=0;i<nStartPos.length;i++) Tm\a%Z`U>
fileSplitterFetch.splitterStop(); >=1Aa,_tc
QpCTHpZ
(}m2}
} U0=: `G2l
} qr4.s$VGs*
//负责部分文件的抓取 YWAH(
**FileSplitterFetch.java # Rhtaq9
*/ mor[AJ
package NetFox; p(>D5uN_}5
1z3>nou2{
fG zx;<0P!
import java.io.*; U4=m>Ty
import java.net.*; qC6@
J4%"38l
#f@}$@
public class FileSplitterFetch extends Thread { 1>=%TIO)
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hx!:F"#
String sURL; //File URL .cm9&&"Z
long nStartPos; //File Snippet Start Position [}I|tb>Pg
long nEndPos; //File Snippet End Position {4{X`$
int nThreadID; //Thread's ID vM?,#:5
boolean bDownOver = false; //Downing is over <ivq}(%72
boolean bStop = false; //Stop identical v]\T&w%9
FileAccessI fileAccessI = null; //File Access interface ioBYxbY`
^+w1:C5
v:"Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l}@C'Np
{ !Qq~lAJO;
this.sURL = sURL; Lb#PiTJI
this.nStartPos = nStart; -HF1c
this.nEndPos = nEnd; `-MCI)Fq_R
nThreadID = id; &o]fBdn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cJ\1ndBH
} vRb7=fXf
T_[5 ZYy
[Lcy &+
public void run() VIaj])m
{ (&-I-#i
while(nStartPos < nEndPos && !bStop) eus@;l*
{ K5 EJ#1ov
t>P[Yld"
G<P/COI#M5
try{ [0D.+("EW
URL url = new URL(sURL); q'9;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d ATAH}r&
httpConnection.setRequestProperty("User-Agent","NetFox"); [HhaBy9
String sProperty = "bytes="+nStartPos+"-"; CF6qEG6
httpConnection.setRequestProperty("RANGE",sProperty); #y'p4Xf
Utility.log(sProperty); 7^;-[?l
$9h^tP'CV
Pv|sPIIB7
InputStream input = httpConnection.getInputStream(); ymn@1BA8J
//logResponseHead(httpConnection); _hgGF9
ydMhb367|
f\FqZ?w
byte[] b = new byte[1024]; 0v#p4@Z
int nRead; /IlO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _FU}IfG>t
{ 3:<[;yo
nStartPos += fileAccessI.write(b,0,nRead); F-XMy>9
//if(nThreadID == 1) XZ2 ji_D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w\M"9T
} fZ(k"*\MZ
XP[~ :+
r?9".H
Utility.log("Thread " + nThreadID + " is over!"); 3e>U(ES
bDownOver = true; e~SRGyIww
//nPos = fileAccessI.write (b,0,nRead); +i[@+`
} v|dt[>G
catch(Exception e){e.printStackTrace ();} b'I@TLE')
} 3lbGG42:
} <E:_9#Z0sc
R[kF(C&
&UVqFo
//打印回应的头信息 qT01@Bku
public void logResponseHead(HttpURLConnection con) dGUiMix{N
{ A@;{#.O
for(int i=1;;i++) |n;5D,r0C
{ C)~%(< D
String header=con.getHeaderFieldKey(i); OnyAM{$g
if(header!=null) T+PERz(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `4e| I.`^r
Utility.log(header+" : "+con.getHeaderField(header)); Y5y7ONcn
else ;X:Bh8tEV
break; 8K@e8p( y
} oN)I3wO$
} RRro.r,
d6ifJ
E B! ,t
public void splitterStop() RU~Pa+H
{ TEbIU8{Y
bStop = true; i6S["\h>
} YV'B*arIA
Esm=sPW
%0({MU
} l3y}nh+ 8
P~V ^Efz{
J\N&u#
/* Od~e*gA8
**FileAccess.java *q;83\
*//文件访问(定位，写) T+S\'f\
package NetFox; RB6TM
import java.io.*; nm)/BK
JEK_W<BD
;&!QN#_
public class FileAccessI implements Serializable{ \9~Q+~@{G
e(FT4KD~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >p`i6_P0P/
RandomAccessFile oSavedFile; \=$G94%
long nPos; aiZZz1C
JxKd
wKoar
public FileAccessI() throws IOException 6B Hdc
{ 6W~JM^F
this("",0); ztAC3,r]
} BqpJvRJd
L=.@hs
6G(K8Q{>
public FileAccessI(String sName,long nPos) throws IOException .yHK
{ FbH@qHSH
oSavedFile = new RandomAccessFile(sName,"rw"); [q/eRIS_
this.nPos = nPos; Q(R-8"
oSavedFile.seek(nPos); ?X\uzu
} n]nJ$u1u
)TBm?VMe
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public synchronized int write(byte[] b,int nStart,int nLen) Fu% n8
{ >"z`))9
int n = -1; FE:}D;$
try{ ^W`RBrJay
oSavedFile.write(b,nStart,nLen); x_<,GE@
n = nLen; 3JD"* <zs
} 9yu#G7
catch(IOException e) 5g;mc.Cvt
{ I0;gTpt9
e.printStackTrace (); zm_8{Rta}
} ZkdSgc')
>.H}(!
^)'D eP/
return n; y5?kv-"c
} {DE4PE`
X_)I"`
) r"7"i
} W}|k!_/
Z`Jt6QgW
BAG#YZB
/* nITkgN:s
**SiteInfoBean.java G7KOJZb+D
*/ %|ioNXMu
package NetFox; UMMGT6s,E8
IR&b2FTcU
n\$.6 _@x
public class SiteInfoBean { L+mHeS l
#KuBEHr
:bCswgd[
private String sSiteURL; //Site's URL wzcv[C-x
private String sFilePath; //Saved File's Path &V%faa1
private String sFileName; //Saved File's Name sp_19u
private int nSplitter; //Count of Splited Downloading File 2_Zn?#G8dl
z~i>GN_
+(`.pa z@
public SiteInfoBean() AmUH]+5KT
{//nSplitter的缺省值为5 MM&qLAa"f
//default value of nSplitter is 5 K_;?Sr=
this("","","",5); [<}W S} .
} zFY$^Oz"_
+x?8\
qWXw*d1]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^`RMf5i1m
{ '#yIcV$
sSiteURL= sURL; 2+K-I
sFilePath = sPath; D+w?
sFileName = sName; ty@D3l
this.nSplitter = nSpiltter; {@'#|]4y.
R <&U]%FD
0Ca/[_
} h?fp(
@udc/J$
=(bTS n
public String getSSiteURL() \_)mWK,h
{ p77=~s
return sSiteURL; \ >#y*W<
} Z4{N|h?
2ppJ;P{k
*8/cd0
public void setSSiteURL(String value) l=a<=i
{ hn$jI5*`
sSiteURL = value; YWDd[\4
} II\}84U2 .
?9T,sX:
R[#B|$
public String getSFilePath() R$">
{ $_|jI ^
return sFilePath; n8q%>.i7
} Y+EwBg)co
aCyn9Y$=
D+h`Z]"|
public void setSFilePath(String value) R0nUS<b0
{ ,0?3k
sFilePath = value; qg*xdefQ%
} xj5MKX{CJT
l\u5RMS('
3'7X[{uBr
public String getSFileName() n0uL^{B
{ awLSY:JI
return sFileName; GwG(?_I"
} MEtKFC|p
]XWtw21I1
D/z*F8'c
public void setSFileName(String value) &}0#(Fa`
{ )>pIAYCVP
sFileName = value; C2L=i3R
} JycC\s+%E
DRRy5+,I
V|4k=_-
public int getNSplitter() .G/RQn]x}
{ |KSoS#Y
return nSplitter; oCKn
} WVx^}_FD0
& 5'cN
/vqsp0e"H
public void setNSplitter(int nCount) 3B4C@ {
{ xfqU atC
nSplitter = nCount; zB6&),[,v
} 9"dZ4{\!
} //#]CsFiP
OV-#8RXJ
K48QkZ_gY
/* h3p~\%^
**Utility.java 8>:u%+C1c
*/ W)`H(J
package NetFox; jVSU]LU E
h~#.s*0.F
Hc\oR(L
public class Utility { (V`ddP-
~b9fk)z!
.zJZ*\2ob
public Utility() WwLV^m]
{ sw,p6T[
9n3.Ar
djDE0-QxcR
} g7K<"Z {M
Jx8DVjy
//线程睡眠 UFj/Y;
public static void sleep(int nSecond) Rts}y:44
{ UJ&gm_M+kL
try{ %vU*4mH
Thread.sleep(nSecond); x' 3kHw
} %;O# y3,
catch(Exception e) okBaQH2lUl
{ "':SWKuMx
e.printStackTrace (); Y_nlIcu
} / KKA/
} z|zd=3c
p49T3V
//日志 .1[pO_
public static void log(String sMsg) I!~3xZ
{ QaAMiCZFR
System.err.println(sMsg); ?WrL<?r)}U
} inyS4tb
?MJ5GVeH
w)Y}hlcq
public static void log(int sMsg) 1<wolTf
{ L$; gf_L
System.err.println(sMsg); d)v!U+-|'
} WZ ,t~TN
} >fgV!o4
w%kaM=
%&4\'lE
/* Xgo`XsA
**TestMethod.java PjU.4aZ
*/ *G,r:Bnb
package NetFox; o%v,6yv
`Ro>?H
z9^_5la#
public class TestMethod { 2Zi&=Zj"
[Mlmn$it
4,ewp coC%
public TestMethod() s;:quM
{ ///xx/weblogic60b2_win.exe 4?~Ei[KgQn
try{ d6"B_,*b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E>qehs,g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cONfHl{
SiteFileFetch fileFetch = new SiteFileFetch(bean); `aaT #r
fileFetch.start(); .%mjE'
} i-&"1D[&
catch(Exception e){e.printStackTrace ();} *q(HW
|r53>,oR<:
6 ZVD<C:\
} |(R[5q
ZRCUM"R_
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public static void main(String[] args) zuBfkW95+
{ Q37zBC0
new TestMethod(); `O}bPwa{>
} Z/I`XPmk
} ^s?i&K,!
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