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)); NLG\*mQ
} Q!V:=d
for(int i=0;i<nEndPos.length-1;i++) S_Wq`I@b
{ 1Z @sh>X|
nEndPos = nStartPos[i+1]; s_VcC_A
} 9*ZlNZ
nEndPos[nEndPos.length-1] = nFileLength; sg2%BkTI
} E1OrL.A6
} mY4pvpZw8
R)Arr77
#O\as~-
//启动子线程 $Vq5U9-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xn503,5G*7
for(int i=0;i<nStartPos.length;i++) 5}ftiy[Yc
{ :ZIa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pa+'0Y]71
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -kMw[Y
nStartPos,nEndPos,i); 1*dN. v:5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c:7F 2+p
fileSplitterFetch.start(); n-"(~
} ka\{?:r,8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W3/bM>1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $KGMAg/H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fPUr O
nEndPos = " + nFileLength); VYkh@j
// fileSplitterFetch[nPos.length-1].start(); 89(qU
pQ:^ ziwa3
1Ng.Ukb
//等待子线程结束 Z}uY%]
//int count = 0; ~at@3j}W
//是否结束while循环 /u4RZ|&as
boolean breakWhile = false; 'A7!@hVy
8lYA6A
wPjq B{!Q
while(!bStop) ZxwrlaA
{ %N<5ST>(
write_nPos(); `M6"=)twu
Utility.sleep(500); jo<xrn\
breakWhile = true; HC6U_d1-6
EXr2d"
JpC=ACF
for(int i=0;i<nStartPos.length;i++) X_o#!
{ e,e(t7c?d
if(!fileSplitterFetch.bDownOver) /h+ W L
{ .k]`z>uv
breakWhile = false; 6Lq`zU^
break; v-3VzAd=*&
} nXLz<wE
} '@.6Rd 8
if(breakWhile) znsQ/[
break; zY_J7,0g
G^k'sgy.
5+M,X kg
//count++; `5?0yXK
//if(count>4) L?d?O
// siteStop(); }h45j84)
} <WZ{<'ajI
?Te#lp;`~
u_^mN9h
System.err.println("文件下载结束！"); IRm}?hHf
} nD BWm`kN
catch(Exception e){e.printStackTrace ();} t[`LG)
} Gg'!(]v
]i.N'O<p
QX<n^W
//获得文件长度 A,<5W }
public long getFileSize() {wz)^A sy
{ ,^?g\&f(
int nFileLength = -1; 1]Xx{j<
try{ mcd{:/^?
URL url = new URL(siteInfoBean.getSSiteURL()); wG[nwt0L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pl:4`oY3
httpConnection.setRequestProperty("User-Agent","NetFox"); M=Ze)X\E*'
DlUKhbo$g
Q`9c/vPU
int responseCode=httpConnection.getResponseCode(); UXBWCo;-
if(responseCode>=400) '/u|32
{ #MA6eE'R
processErrorCode(responseCode); sWr;%<K
return -2; //-2 represent access is error p6<JpW5@_
} Ux=~-}<-w
#("M4}~
,yGbMOV
String sHeader; >k\pSV[
@\y{q;
O]PM L`
for(int i=1;;i++) uMw6b=/U
{ Q&]|W Xv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w/*G!o-<
//Utility.log(in.readLine()); toPbFU'
sHeader=httpConnection.getHeaderFieldKey(i); 7?whxi Qs
if(sHeader!=null) #]jl{K\f#X
{ ,6{z
if(sHeader.equals("Content-Length")) MWv@]P_0p!
{ a -Pz<*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'Eur[~k
break; ev;&n@k_I
} )\Q(=:
} D;> 7y}\
else 'z8FU~oU
break; t,fec>.
} uM`i!7}
} jlj ge=#c2
catch(IOException e){e.printStackTrace ();} )ovAGO
catch(Exception e){e.printStackTrace ();} .b]sQ'
"KP]3EyPc
~ZVz sNrx
Utility.log(nFileLength); 6U !P8q
nm1dd{U6^
d78 [(;
return nFileLength; @6'~RD.
} 5K1cPU~o_b
O"'xAPQW
v'S]g^
//保存下载信息（文件指针位置） &K0b3AWc
private void write_nPos() `CVkjLiy
{ B%6cgm,
try{ Kz42AC
output = new DataOutputStream(new FileOutputStream(tmpFile)); z='%NZY
output.writeInt(nStartPos.length); 0beP7}$
for(int i=0;i<nStartPos.length;i++) /X_L>or
{ #Q!Xz2z2
// output.writeLong(nPos); m:h6J''<Z*
output.writeLong(fileSplitterFetch.nStartPos); **h4M2'C
output.writeLong(fileSplitterFetch.nEndPos); AZQQge
} ?) y}HF
output.close(); 5=C?,1F$A
} !Sn|!:N4
catch(IOException e){e.printStackTrace ();} x\G%
catch(Exception e){e.printStackTrace ();} m*]`/:/X[
} i=#`7pt%'a
$b|LZE\bU.
+ kMj|()>\
//读取保存的下载信息（文件指针位置） :u,.(INB
private void read_nPos() D:Q#%wJ
{ Vq+7 /+2"
try{ R)66qRf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *eoH"UFYQ#
int nCount = input.readInt(); d/9YtG%q
nStartPos = new long[nCount]; m&gd<rt/
nEndPos = new long[nCount]; 3l<qcKKc
for(int i=0;i<nStartPos.length;i++) ~QbHp|g
{ P_5aHeiJ
nStartPos = input.readLong(); qhY+<S9
nEndPos = input.readLong(); wL8ji>"
} K2Abu?
input.close(); /7D5I\
} .JLJ(WM
catch(IOException e){e.printStackTrace ();} teS>t!d
catch(Exception e){e.printStackTrace ();} "/6#Z>y
} 1k6asz^T
OY{fxBb
{C5:as
private void processErrorCode(int nErrorCode) eP]y\S*P
{ #1haq[Uv7
System.err.println("Error Code : " + nErrorCode); /iO"4%v
} u*@R`,Y
+H3~Infr4f
f`Fj-<v
//停止文件下载 ch8VJ^%Ra1
public void siteStop() #4m5I="
{ VF2,(f-*
bStop = true; 6#U~>r/
for(int i=0;i<nStartPos.length;i++) ]!AS%D`
fileSplitterFetch.splitterStop(); FXBmatBck
~k&b
I4N7wnBp
} zU!{_Ao9
} J`5+Zngr
//负责部分文件的抓取 bpBn3f`?*
**FileSplitterFetch.java Z(6.e8fK
*/ tAN!LI+w
package NetFox; oUnb-,8n
9$$ Ijf
F)cCaE;
import java.io.*; 4nm.ea|
import java.net.*; ^rJTlh 9
5.5kH$;>
|/K|Vwa
public class FileSplitterFetch extends Thread { <}WSYK,zUY
hn2:@^=f
.F7?}8>Z
String sURL; //File URL w0g@ <( 3
long nStartPos; //File Snippet Start Position v>LK+|U
long nEndPos; //File Snippet End Position YxM\qy{Vr
int nThreadID; //Thread's ID @FIL4sb
boolean bDownOver = false; //Downing is over #[M^Q h
boolean bStop = false; //Stop identical ywp_,j9F
FileAccessI fileAccessI = null; //File Access interface c(=>5
zY\u" '4
PFp!T [)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IQ<G.
{ Sk53Lc
this.sURL = sURL; :(XyiF<Ud
this.nStartPos = nStart; TQO|C?
this.nEndPos = nEnd; ^rfR<Q`
nThreadID = id; 1SjVj9{:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :? B4q#]N
} <2]h$53y!
CCG5:xS
fh`Y2s|:7R
public void run() 6k0Awcr
{ nX:E(9q7c
while(nStartPos < nEndPos && !bStop) 9!=4}:+
{ ,5zY1C==Ut
6kp)'wz`
A~Sc ] M
try{ +>C26Q
URL url = new URL(sURL); Y[L,rc/j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |5(un#
httpConnection.setRequestProperty("User-Agent","NetFox"); _XZK2Q[
String sProperty = "bytes="+nStartPos+"-"; q}Po)IUT`5
httpConnection.setRequestProperty("RANGE",sProperty); =*'yGB[x)
Utility.log(sProperty); s7yKxg+`{
!y_L~81?
)>h3IR
InputStream input = httpConnection.getInputStream(); &5K3AL
//logResponseHead(httpConnection); uH$hMg
!PoyM[Z"f
=T3{!\tH
byte[] b = new byte[1024]; (QIU3EN
int nRead; 4OM ]8I!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 10zM8<bl
{ x3Cn:F
nStartPos += fileAccessI.write(b,0,nRead); UZt3Ua&J
//if(nThreadID == 1) &c-V QP(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Po=:-Of:
} ,9G'1%z,
xytWE:=
H9jlp.F
Utility.log("Thread " + nThreadID + " is over!"); {G=>WAXo
bDownOver = true; 5(#z)T
//nPos = fileAccessI.write (b,0,nRead); 8-+# !]
} ]uhG&: }
catch(Exception e){e.printStackTrace ();} $xW9))
} 0(c,J$I]Z!
} &kdW(;`
S".|j$
<P1nfH
//打印回应的头信息 R5b,/>^'A
public void logResponseHead(HttpURLConnection con) MMjewGxe
{ ):G+*3yb
for(int i=1;;i++) /|U;_F Pmc
{ +xIVlH9`Q
String header=con.getHeaderFieldKey(i); 2Ax(q&`9
if(header!=null) dKPXs-5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "8a V~]~Dj
Utility.log(header+" : "+con.getHeaderField(header)); R{brf6,
else ]z7pa^
break; J",Cwk\
} >1Iw!SO+
} [i~@X2:Al
Z-t qSw8n
pDP* 3
public void splitterStop() 6$PQ$
{ =^M Q 4
bStop = true; b/.EA'/
} TQt[he$O
d^?e*USh
|oeg'T
} UBv#z&@[
m6 M/G
g#{7qmM
/* $n8&5<
**FileAccess.java Dp*:oMATx0
*//文件访问(定位，写) @QJPcF"
package NetFox; i`9}">7v~
import java.io.*; &gV9h>Kc#
hHMp=8J7
q\P{h ij
public class FileAccessI implements Serializable{ 7KC2%s#7
FFwu$S6e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :p<:0W2!
RandomAccessFile oSavedFile; /3L4K
long nPos; G|&$/]~
[Ketg
C.=%8|Zy
public FileAccessI() throws IOException }rVLWt
{ N["M "s(N
this("",0); J|V*g]#kP
} :ldI1*@i<
JvT#Fxjk
=`}|hI
public FileAccessI(String sName,long nPos) throws IOException <vg|8-,#m
{ V:D?i#%,z
oSavedFile = new RandomAccessFile(sName,"rw"); !=vsY]
this.nPos = nPos; !+hw8@A
oSavedFile.seek(nPos); /$qB&OWJn
} 0^P9)<k'
A@.ruG$
, Z1 &MuV
public synchronized int write(byte[] b,int nStart,int nLen) rIv#YqT
{ F9_X^#%L
int n = -1; z2.OR,R}]
try{ ODCN~7-@
oSavedFile.write(b,nStart,nLen); H-& ktQWK3
n = nLen; xjDaA U,
} q/7T-"q/G
catch(IOException e) L{f0r!d|
{ *~#`LO
e.printStackTrace (); {R~L7uR@O
} M1DV9~S
;cv\v(0
)1 0aDTlr
return n; QSYKYgxC
} `+(JwQC4
EffU-=?%!
Hg]iZ,8?
} %E":Wv
>\Iy <M
Em<J{`k6
/* 5n2}|V$VqP
**SiteInfoBean.java a,t]>z95
*/ rt! lc-g%/
package NetFox; zW95qxXg
65c#he[_Y
fxD|_
public class SiteInfoBean { vf<Tq
}WNgKw
]waCYrG<sY
private String sSiteURL; //Site's URL <ot%>\C
private String sFilePath; //Saved File's Path :;3y^!
private String sFileName; //Saved File's Name @:u2{>Yl
private int nSplitter; //Count of Splited Downloading File 5)K?:7
=-uk7uZM
7:)$oH
public SiteInfoBean() Z+;670Z
{//nSplitter的缺省值为5 V,3$>4x
//default value of nSplitter is 5 1B`0.M'd
this("","","",5); O;;vz+ j
} ^@q$c
V/DdV}n!
P4"EvdV7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }'TZ)=t{J
{ '$CJZ`nt
sSiteURL= sURL; {uO2m*JrI
sFilePath = sPath; ByXcs'
sFileName = sName; JA?P jo
this.nSplitter = nSpiltter; / ='/R7~
}15ooe%
0'y3iar
} c:`&QDF
9y"\]G77E
,OO0*%
public String getSSiteURL() kasx4m]^
{ ^p7Er!
return sSiteURL; e,0Gc-X[B
} dzc.s8T(0
5zII4ukn*
b"#|0d0
public void setSSiteURL(String value) [hXU$Y>"0
{ /&'rQ`nd
sSiteURL = value; cd*F;h
} ,W<mz7Z(@
r \]iw v
wkZ}o,{*:
public String getSFilePath() 8:0.Pi(ln@
{ 9Lxa?Y1
return sFilePath; 9k!#5_ M
} (A8X|Y
5eSmyj-W
9G}Crp
public void setSFilePath(String value) J\kv}v
{ "(#]H;!W
sFilePath = value; )0Lv-Gs
} oBTRO0.s+
ul3._Q
gnSb)!i>z
public String getSFileName() {p(.ckze+
{ KrT+Svm
return sFileName; H23-%+*J
} pVm'XP
GKKf#r74
^cF_z}Zi+
public void setSFileName(String value) =h2zIcj
{ "S@%d(lg
sFileName = value; ~nG?>
} {__"Z<
6rOd80\
sjV>&eb
public int getNSplitter() !j?2HlIK+
{ _/5mgn<GK
return nSplitter; H{CG/+x
} E7qk>~Dg
qTL]
miZ&9m
public void setNSplitter(int nCount) aE(j_`L78
{ jDO[u!J6.%
nSplitter = nCount; J0M7f]
} *:3`$`\54
} ( XoL,lJ
Ju#t^P
H:BWv08~5
/* A/EW57v"
**Utility.java %g4G&My@J
*/ >;.'$-
package NetFox; (r?41?5K
{1V~`1(w
)xuvY3BPB?
public class Utility { Pp[?E.]P
v(/T<^{cuk
Zi fAn
public Utility() TPrqb
{ Gt^Fj&^
u<l[S
Wo@0yF@
} o'Byuct
UmSy p\i
//线程睡眠 K$dSg1t
public static void sleep(int nSecond) |A#pG^
{ @e_ bG@
try{ lXS.,#lp
Thread.sleep(nSecond); T8,?\7)S9
} tTB,eR$
catch(Exception e) 4jlUyAD
{ I=)u:l c
e.printStackTrace (); O$ 7R<V
} %(,Kj ~0
} *eAsA(;
i[_WO2
//日志 C$~2FTx
public static void log(String sMsg) >'^Tp7\
{ Uv~r]P)
System.err.println(sMsg); Y9)uy 8c
} %OeA"#
<0r2m4z
w NlC2is
public static void log(int sMsg) mjDaus59
{ 'Tni;
System.err.println(sMsg); 8[Ssrk
} h|tdK;)
} VFj}{Y
VL5GX(
o.ntzN
/* P".CZyI-i
**TestMethod.java TzT(aWP"
*/ v"VpE`z1#
package NetFox; }j^asuf~c
?CgqHmf\$
'`#sOH
public class TestMethod { IvFxI#.ju
l&@]
B zmmE2~*
public TestMethod() A{Jp>15AVg
{ ///xx/weblogic60b2_win.exe diF-`~
try{ p0jQQg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YL_M=h>P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |N%?7PZ(
SiteFileFetch fileFetch = new SiteFileFetch(bean); fz[o;GTc
fileFetch.start(); kQ5mIJ9(
} LD]a!eY
catch(Exception e){e.printStackTrace ();} slC 38
n.&z^&$w$
9?5'>WO
} b*w@kLLN
?6;9r[ p
W_:3Sj l'
public static void main(String[] args) i^9,.$<1
{ =]k0*\PS
new TestMethod(); ),ur!v
} LO8`qq*rq
} SJg4P4|
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