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)); kwL)&@
} Ih7Eq/iu
for(int i=0;i<nEndPos.length-1;i++) ry\']\k
{ o{he)r6)_
nEndPos = nStartPos[i+1]; VM,ZEt3Vy
} Za6oYM_z
nEndPos[nEndPos.length-1] = nFileLength; Hj\~sR$L-
} aOHCr>po,
} ul?BKV+3E
qLP+@wbJ
=c,gK8C
//启动子线程 oB\Xl)A<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nAg(lNOWN
for(int i=0;i<nStartPos.length;i++) zoJ;5a.3B
{ K;qZc\q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PWMaB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zEB1Br,
nStartPos,nEndPos,i); }j?S?=;m=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zvf]}mNx
fileSplitterFetch.start(); ;Wa{q.)
} &~%@QC/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N>R%0m<e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ie(7m|.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (<l2 ^H
nEndPos = " + nFileLength); v'!Ntk
// fileSplitterFetch[nPos.length-1].start(); 3+-(;>>\
Q]wM/7
wuzz%9;@B
//等待子线程结束 XNUqZ-M:
//int count = 0; [&CM-` N
//是否结束while循环 a~*V
boolean breakWhile = false; hwzUCh 5!
g#4gGhI
+V@=G &Ou0
while(!bStop) $3TTHS o
{ i .N1Cvp&
write_nPos(); !_9$[Oq~
Utility.sleep(500); h)rf6*hw
breakWhile = true; i6d$/yP"
UTQKlwPa
HD{`w1vcN
for(int i=0;i<nStartPos.length;i++) k&/)g3(N(
{ IDh`0/i]
if(!fileSplitterFetch.bDownOver) qN[7zsaj
{ N%f!B"NQ
breakWhile = false; nvPE N
break; D-GU"^-9
} H/k W :k
} n@;x!c< +
if(breakWhile) $3'+V_CZ3
break; L"iyjL<M
~ ZL`E
Fnpn_O XlH
//count++; t^,Qy.L0
//if(count>4) 358/t/4{p
// siteStop(); Pm^N0L9?q
} @;fE%N
~5NGDT#L*
DOVX$N$3
System.err.println("文件下载结束！"); HF: T]n,
} LUNs|\&
catch(Exception e){e.printStackTrace ();} Wi?%)hur
} X-1Vp_(,TP
;q; C^l
Jyci}CU3\Q
//获得文件长度 7V{"!V5
public long getFileSize() 66<\i ltUQ
{ LU,"i^T
int nFileLength = -1; " ^baiN@ac
try{ i=UTc1
URL url = new URL(siteInfoBean.getSSiteURL()); 7f%Qc %B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NNwd;AC
httpConnection.setRequestProperty("User-Agent","NetFox"); -1
L"h@`3o|
I#X2UQzP
int responseCode=httpConnection.getResponseCode(); U%DF!~n
if(responseCode>=400) Bh,)5E^m
{ kc'0NE4oq
processErrorCode(responseCode); %Z[/U
return -2; //-2 represent access is error 1MI7l)D?
} I'9s=~VfY,
+M##mRD
[4Faq3T"
String sHeader; ^D;D8A.
CQHp4_
PdH`_/6
for(int i=1;;i++) "&#WMi
{ d^5SeCs6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '[ g)v
//Utility.log(in.readLine()); 8I\eromG
sHeader=httpConnection.getHeaderFieldKey(i); $U1kP?pR
if(sHeader!=null) Ws*PMK.0
{ < }wAP_y
if(sHeader.equals("Content-Length")) n [Xzo}
{ Ik5jwfz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s#4ew}
break; Zng` oFD
} iQ!
} 7ml0
else y)/$ge_U
break; };m7FO
} !""!sFx)R
} zt)PZff/YQ
catch(IOException e){e.printStackTrace ();} As'M39*V
catch(Exception e){e.printStackTrace ();} ^T&u!{82j
Z!-<rajl
gZ"{{#:}
Utility.log(nFileLength); >3`ctbe
nqxq@.L2
BgWz<k}5M
return nFileLength; e#6&uFce
} 5uV"g5?w
vvsNWA
Xc2B2c
//保存下载信息（文件指针位置） !^l4EL5#
private void write_nPos() RpXs3=9
{ nn)`eR&
try{ tM$0 >E
output = new DataOutputStream(new FileOutputStream(tmpFile)); cCh5Jl@Z
output.writeInt(nStartPos.length); an=+6lIl
for(int i=0;i<nStartPos.length;i++) lDJd#U'V
{ a^XTW7]r
// output.writeLong(nPos); ;Co[y=Z
output.writeLong(fileSplitterFetch.nStartPos); wEfz2Eq
output.writeLong(fileSplitterFetch.nEndPos); C*s0r;
} rF'^w56
output.close(); R'9@A\7#
} %V%#y $l
catch(IOException e){e.printStackTrace ();} JQ@`EV9,
catch(Exception e){e.printStackTrace ();} 9<A\npD
} HcBH!0
j,56Lh%1
Vr-3M+l=O
//读取保存的下载信息（文件指针位置） L`\`NNQC
private void read_nPos() *mQDS.'AB@
{ RC8)f8n
try{ ^KZAYB9C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *)NR$9lGv
int nCount = input.readInt(); B)DC,+@$
nStartPos = new long[nCount]; Jl>at
nEndPos = new long[nCount]; D){"fw+b
for(int i=0;i<nStartPos.length;i++) n.a=K2H:V
{ l<aqiZSY
nStartPos = input.readLong(); LN.Bd,
nEndPos = input.readLong(); *K}z@a_
} cPx~|,)l
input.close(); \L9?69B~
} V8nz-DL{
catch(IOException e){e.printStackTrace ();} g^z5fFLg/8
catch(Exception e){e.printStackTrace ();} Tw}?(\ya
} D0#T-B\#
2%5^Fi
?79SPp)oo
private void processErrorCode(int nErrorCode) {V%%^Zhwy
{ V<HOSB7
System.err.println("Error Code : " + nErrorCode); AU\xNF3
} t*Vao
j$|j8?
qP;{3FSkAF
//停止文件下载 o0aO0Y
public void siteStop() *X=@yB*aK
{ L,L~ .E
bStop = true; r;cI}'
for(int i=0;i<nStartPos.length;i++) m6_~`)R8
fileSplitterFetch.splitterStop(); Ko$ $dkSE
*h*j%
C,|nmlDN
} yhSk"e'G
} -[zdX}x.:
//负责部分文件的抓取 c YM CfP
**FileSplitterFetch.java 5U-p'c9IC
*/ ]^*_F
package NetFox; QH7V_#6bKP
Jb3>vCIn
ko=aa5c
import java.io.*; vz;7} Zj]
import java.net.*; A*\o c
tA! M
IS,zy+w
public class FileSplitterFetch extends Thread { DnNt@e2|
j}rgOz.
XlPK3^'N)h
String sURL; //File URL <pTQpU
long nStartPos; //File Snippet Start Position er["NSo
long nEndPos; //File Snippet End Position u[V4OU}%
int nThreadID; //Thread's ID fqcU5l[v,
boolean bDownOver = false; //Downing is over !paN`Fz\a
boolean bStop = false; //Stop identical .N5hV3
FileAccessI fileAccessI = null; //File Access interface s6uF5]M;2
)|U_Z"0H^
cy=I0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7oZ@<QP'
{ nd$H 3sf
this.sURL = sURL; |~@x4J5,
this.nStartPos = nStart; aW0u8Dz
this.nEndPos = nEnd; RNv{n mf
nThreadID = id; Iz6ss(UJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U8-Q'1IT&
} j>$=SMc
pau*kMu^}
tJUVw=
public void run() n9]IBIthe
{ <O \tC81
while(nStartPos < nEndPos && !bStop) 6Gs{nFw
{ ]regi- LGU
DAjG*K{
+"k.E x0:
try{ v2/yw,
URL url = new URL(sURL); gHQPhe#n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TqS2!/jp
httpConnection.setRequestProperty("User-Agent","NetFox"); &u+yM D
String sProperty = "bytes="+nStartPos+"-"; 0M$#95n
httpConnection.setRequestProperty("RANGE",sProperty); 2wB.S_4"-<
Utility.log(sProperty); Mam8\
OD
E:08%4O
InputStream input = httpConnection.getInputStream(); ad"'O]
//logResponseHead(httpConnection); \@Ee9C13
p&i.)/
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byte[] b = new byte[1024]; %==G+S{
int nRead; TA Ftcs:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~gu=x&{
{ I*^5'N'
nStartPos += fileAccessI.write(b,0,nRead); 44\!PYf7
//if(nThreadID == 1) 6N9 c<JC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]YCPyc:
} W*YxBn4
lemVP'cn
pTcbq
Utility.log("Thread " + nThreadID + " is over!"); *-?Wcz
bDownOver = true; 3.Ji5~
//nPos = fileAccessI.write (b,0,nRead); Oq*n9V
} tRLE,(S,-
catch(Exception e){e.printStackTrace ();} L/Hv4={
} "/Y<G
} "Z;~Y=hC13
z'7#"D
<KKDu$W|T
//打印回应的头信息 MQwIPjk8
public void logResponseHead(HttpURLConnection con) ^ Xm/
{ X.s*>'
for(int i=1;;i++) tS?a){^:c
{ t";{1.
String header=con.getHeaderFieldKey(i); t:\l&R&
if(header!=null) ~V @;(_T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GHv{
Utility.log(header+" : "+con.getHeaderField(header)); Vd,' s
else 7e1dEgn
break; z<a$q3!#
} I`22Zwq:
} T36x=LX
-M6L.gi)oJ
tC^ 1}
public void splitterStop() '9'l=Sh
{ gXLCRn!iR
bStop = true; @zo7.'7P
} G;/Q>V
YnSbw3U.I
5QAdcEcN@O
} 0Y7$d`
B1E$v(P3M
'0Lov]L
/* S"zk!2@C
**FileAccess.java x5oOF7#5
*//文件访问(定位，写) E(_KN[}S
package NetFox; K]X`sH:
import java.io.*; yk<VlS
^pj>9%
md?b*
public class FileAccessI implements Serializable{ eI^gV'UK
{|z#70
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?{eY\I
RandomAccessFile oSavedFile; F$i$a b
long nPos; R<|ejw
R\*)@[y9l
s2^B(wP
public FileAccessI() throws IOException sm1;MF]/u
{ ^00{Hd6
this("",0); 'f*O#&?
} fuMN"T 6%+
UgR:qjI
#:#Dz.$L
public FileAccessI(String sName,long nPos) throws IOException 6a*83G,k
{ RwW$O@0
oSavedFile = new RandomAccessFile(sName,"rw"); J@QdieW6
this.nPos = nPos; vs+QbI6>-
oSavedFile.seek(nPos); wZjlHe
} fp{G|.SA
8.yCA
c_#*mA"+
public synchronized int write(byte[] b,int nStart,int nLen) 1fY>>*oP
{ ><=rIhG%H@
int n = -1; }z wX
try{ Yrxk Kw#
oSavedFile.write(b,nStart,nLen); LKx`v90p
n = nLen; fJy)STQ4
} .#0H{mk
catch(IOException e) 'd/*BjNp)
{ 9*\g`fWc}{
e.printStackTrace (); /g@^H/DO
} K\(6rS}N
7(Cx!Yb
lm$;:Roj*
return n; vM(Xip7
} 3rNc1\a;
T`\]!>eb
L+.H z&*@
} ul@3 Bt
I^G^J M!
h=6xZuA\
/* F+ukAT
**SiteInfoBean.java &tj0M.-
*/ 6aY>lkp
package NetFox; q>-R3HB
rLzW`
FaY_0G;y
public class SiteInfoBean { \0?$wIH?
pDn&V(
,[X_]e;
private String sSiteURL; //Site's URL J4>;[\%m
private String sFilePath; //Saved File's Path |@RpWp>2
private String sFileName; //Saved File's Name b9uBdo@o
private int nSplitter; //Count of Splited Downloading File vd (?$
ARF\fF|<2
1k[GuG%/K
public SiteInfoBean() 6{=_718l`
{//nSplitter的缺省值为5 vk'rA{x
//default value of nSplitter is 5 8eJE>g1J
this("","","",5); !n<o)DsZR
} m[:K"lZ ]2
]-:6T0JuS
GoIQ>n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0Z HDBh
{ TQc@lR!
sSiteURL= sURL; xS8,W
sFilePath = sPath; M'2r@NR8
sFileName = sName; g)R1ObpZ
this.nSplitter = nSpiltter; o=_c2m
RlRs}yF
VEs5;]#<2D
} G\=_e8(
Kkv<"^H
g^l RG3a
public String getSSiteURL() %;|0
{ d1]i,C~Y
return sSiteURL; H0>yi[2f
} f~ZEdq8
fu4!t31
0V`[Zgf
public void setSSiteURL(String value) dv!r.
{ ,j178EX
sSiteURL = value; }y6q\#G
} #U ASH&
pRi<cO
C6jR=@42Q
public String getSFilePath() zN!j%T.e
{ +Gh7^v|"
return sFilePath; Qxa{UQh}9
} D4Etl5k
(=c1
N3%*7{X 9
public void setSFilePath(String value) |=K_F3aJ
{ "2{%JFE
sFilePath = value; I ~$1Lu`~
} P@0Y./Ds
|"]PCb)!
I=IjdwbH
public String getSFileName() wK!~tYxP
{ h|)vv4-d|
return sFileName; vH[Pb#f-
} {mTytT
:iPym}CE
)9L/sKz
public void setSFileName(String value) 2k5/SV X
{ $yu?.b 9H#
sFileName = value; ub K7B |p
} rv7{Ow_Y
qCPmbg
%d;ezY'2
public int getNSplitter() (sTuG}
{ t ls60h
return nSplitter; 1m@^E:w
} 9 OT,TpA
N#ioJ^}n:
X+82[Y,mB.
public void setNSplitter(int nCount) ,S&z<S_
{ rwf^,r"r
nSplitter = nCount; 6b=q-0yj
} L'Q<>{;Ig
} #FH[hRo=6
"r'ozf2\
|E)aT#$f'
/* \Qy$I-Du
**Utility.java ",Cr,;]
*/ PXk?aJ
package NetFox; !L24+$
,"2TArC'z
<AoXEuD
public class Utility { @n+=vC.xO
?cy4&]s
@It>*B yB.
public Utility() #,NvO!j<4
{ #& ?g %'
h2Bz F
fV\]L4%
} DN] v_u+}
)>a B
//线程睡眠 5&!c7$K0
public static void sleep(int nSecond) {XCf-{a]~
{ 9KuD(EJS
try{ quxdG>8
Thread.sleep(nSecond); * ?Jz2[B
} r@G#[.*A>
catch(Exception e) WyhhCR=;
{ PBjmGwg7
e.printStackTrace (); s^8u&y)3
} PoSpkJH
} a;AzY'R
{KL5GowH
//日志 , X{>
public static void log(String sMsg) Zu*K-ep"
{ X[yNFW}S2W
System.err.println(sMsg); na+d;h*~y
} 9i q""
#]Y>KX2HG
mN_Z7n;^eh
public static void log(int sMsg) c3TKl/
{ }hpmO-
System.err.println(sMsg); yV_wDeAz
} A!i q->+
} kFLB> j97
GX{XdJD
IH*s8tPc
/* @R|'X
**TestMethod.java |I;$M;'r&
*/ J @IS\9O
package NetFox; <@v]H@E
f. }c7
C#0Qd%
public class TestMethod { Ah69 _>N`S
xg@NQI@7
),}AI/j;zY
public TestMethod() ;]2s,za)qs
{ ///xx/weblogic60b2_win.exe SkQswH
try{ pc]J[ S?P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XRN+`J
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iUk-'
SiteFileFetch fileFetch = new SiteFileFetch(bean); _i0kc,*C\
fileFetch.start(); _l`e#XbG
} 6A R2htN^
catch(Exception e){e.printStackTrace ();} q!~ -(&S
*XOJnyC_H
&EGqgNl
} q'[}9e`Q
w*9br SK
26?W nu60
public static void main(String[] args) W#fZ1E6
{ lCd@jB{
new TestMethod(); 5K%SL1N
} nuQ]8-,
} NE2pL@sk
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